Martinsville Speedway has always been Jimmie Johnson's ace in the hole when it's came to Chase campaigns in the past. If he's been in with chance of the title heading to the half mile "paperclip" short track, then it's been Martinsville that has allowed him to put his foot down and start to pull away to safety from the opposition. With eight career wins here - his most successful track in the NASCAR Sprint Cup Series - there's no place that Johnson feels more at home or is more confident at.

By contrast, Johnson's chief Chase rival in 2013, Matt Kenseth, has never won at Martinsville. In fact, he's managed only three top-five and eight top-10 finishes in 27 career starts at the venue, so the name of the game for Kenseth heading to the circuit on Sunday for the Goody's Headache Relief Shot 500 Powered by Kroger was damage limitation and not let Johnson massively extend the lead he'd taken at Talladega a week before. Anything else would be gravy.

Both men were up at the front right from the start, with Johnson taking the lead away from pole winner Denny Hamlin on lap 2 before the first of what would prove to be a season-high 17 cautions totalling 111 laps (almost a quarter of the 500-lap race) run under yellow. The first caution was a particularly lengthy one for fluid clean up after Carl Edwards got into the back of Jeff Burton at turn 4 and spun the #31 around, also involving Dave Blaney, Travis Kvapil and Ricky Stenhouse Jr. in the aftermath.

The race resumed on lap 20 with Kyle Busch talking the lead from Johnson for a dozen laps before Kenseth took over for the first time on lap 37. Deciding he liked the view, he moved in the furniture and settled down for the first long spell in the lead, amassing a total of 74 laps out in front which raised eyebrows among spectators: had Kenseth finally mastered Martinsville?

The second caution came on lap 88, and once again Carl Edwards was in the thick of it - this time it was Kvapil sent spinning around by the #99. For the second time of the day, Edwards had his spotter relay his apologies as the field pitted for the first time.

Kenseth resumed in the lead ahead of the Hendrick Motorsports pair of Johnson and Gordon, the latter driver almost as successful at Martinsville in his time as Johnson, but not having found his way to victory lane here since 2005. Still, with such proven firepower arrayed against him, it was only a matter of time before Kenseth was forced to give way: it happened on lap 111 when Johnson made a move on the low side and picked up the position, Gordon following his team mate's lead a few minutes later. Those who'd thought that maybe this would be a breakthrough day for Kenseth settled back again in their seats: normal service had been restored.

Johnson's lead continued through a caution on lap 140 for David Reutimann spinning out Bobby Labonte and the ensuing pit stops, through to the next yellow on lap 166 for Kyle Larson's engine letting go and dropping more fluid on the track on the backstretch. Jeff Burton stayed off pit road this time and briefly led at the restart on lap 180, but he was soon displaced by Johnson taking back his rightful crown.

It's just as well he did it quickly, because the next caution came out just three laps later when a group of cars bunched up in turn 1 and tripped over each other: Hamlin, Kasey Kahne, Aric Almirola and Martin Truex Jr. were among those caught up, with Kahne ending up stuck in the grass, Hamlin slewed sideways on the track and Truex with a new accordion design to the front of the #56.

Racing resumed on lap 192 and was under caution again on lap 205 for another multi-car accident, this time for Kurt Busch spinning after contact with Jamie McMurray that left the #78 ripe for getting rammed by Mark Martin in the #14. Kenseth took the lead soon after the restart and was back out in front when Kvapil spun in turn 4 on lap 218.

The Chase contenders were side-by-side for the restart on lap 223, which proved that this year the cars were having a real problem running the high line: anyone stuck on the outside for any length of time - like Johnson, starting from second place - would quickly lose positions unless and until someone took pity and allowed him back into the low line. It would be a trait that persisted throughout the rest of the afternoon, teams even starting to plan pit strategies around whether they would end up with an inside line for subsequent restarts.

And boy, there would be a lot of restarts. The race was so staccato through the middle phase that any attempt at meaningful strategy quickly went out of the window and it just became a matter of fast reactions to the events and what was going on around at any given point. In summary, there was a caution on lap 229 for Reutimann spinning after contact with Truex; Reed Sorenson coming to a stop on track in turn 4 with gear issues on lap 285; debris in turn 1 on lap 298; Landon Cassill spinning out in turn 3 after contact with Kahne on lap 309; Ryan Newman hitting the wall in turn 1 on lap 318 after contact from Kevin Harvick; Truex getting spun on lap 327 by contact with Marcos Ambrose in turn 1; another debris caution on lap 337; Cole Whitt spinning in turn 4 on lap 365; and JJ Yeley similarly going wayward in turn 3 on lap 380.

At one point there had been five caution flags in just 41 laps: even by short track standards, this was bordering on the insane. The cramped, almost claustrophobic circuit was one reason for the cars all falling over each other, but the need to be on the low line was also a big contributor: cars were so desperate to move down (and others already on the low side so motivated to stop them) that contact after contact had sent cars spinning around all afternoon.

In the meantime, the Johnson/Kenseth hegemony at the front had been broken up. Clint Bowyer took the lead on lap 238 after Johnson had pitted under a previous caution; Kenseth had stayed out but fared no better, his older tyres proving a handful and sending him dropping back through the field and out of the top ten even as Johnson worked his way back up in the other direction.

Kenseth pitted under the next caution on lap 289, but his already compromised track position plus an unusually slow stop by the Joe Gibbs Racing crew did nothing for his fortunes or his humour. Meanwhile the front of the race was back in the hands of Gordon and Johnson after the latest round of stops, so in terms of the Chase it was looking increasingly as though once again Martinsville would prove pivotal in turning the championship in Johnson's direction once again.

Kenseth's only hope was to work his way back up through the field while he had fresh tyres, but each time he made any headway another of the rapid-fire cautions foiled his efforts. The team countered by bringing him in for fresh tyres to try and keep his advantage for the next run, only for the same thing to happen again. The driver was not a happy man through this stage of proceedings.

Finally, however, the race started to turn in Kenseth's favour: while Johnson dropped to 20th on his more standard pit stop, Kenseth was working his way to the front. After spells with Hamlin, Bowyer and Elliott Sadler leading the race (the latter by staying off pit road under a caution) it was finally time for Kenseth to regain control of the race on lap 374. There was still a quarter of the race to go, but once again it felt that the balance of power was shifting in Kenseth's favour and away from Johnson, if only by the smallest amount.

At the restart on lap 386 following Yeley's spin, Johnson was trapped on the outside line once again (crew chief Chad Knaus' acerbic comments over the team radio about the #48's fortunes in this regard were a treat, albeit 18 certificate) and promptly fell from sixth to ninth before he could pull into line; that left Kenseth out in front ahead of Hamlin, Brad Keselowski, Burton, Bowyer, Gordon and Busch. There was another brief interruption to proceedings on lap 416 for debris in turn 1 which allowed the drivers to make their last visit to pit road of the way and lay to rest the spectre of fuel conservation runs, and then Kenseth led the field to green on lap 424 for would be prove to be a mercifully, miraculously caution-free final 76 laps all the way to the chequered flag.

Kenseth had the lead, but Gordon was quickly squatting in second place, watching and waiting for any sign of weakness that would allow him to strike. He didn't have all that long to plot his strategy: with a lap time of less than 15s, there was less than 20 minutes remaining in the race and Gordon was under no misapprehension as to how tough an opponent he was facing.

"What would Jimmie Johnson do?" Gordon laughed when asked what had been going through his mind in the final laps. "Or better yet, maybe what would Richard Petty do? The tyres really went away on us there at the end," he admitted.

"I knew this car was good on the short runs, but he was putting a really good run together and we had freed my car up, and at the end there, I think it was a little too free," Gordon admitted. "But every time I saw him slip a wheel, I just tied to conserve my tyres and drive the car real straight into the corner and off the corner; playing with brake bias and everything else.

"I finally saw where he started struggling on the exit," Gordon continued. "I dove in there a couple of times, but I couldn't quite make it. He drove in deep to protect his line and did a heck of a job. Matt drove a really first-class calibre race today and I didn't know if we were going to get him."

But finally he did, and with 20 laps to go he nosed in front and held it there, dislodging Kenseth from the lead and lining himself up for his first win of 2013 - and his eighth at Martinsville, meaning that he now ties for victories here with Johnson himself.

"Jeff's experience got me -I just don't have that much experience running up front here," Kenseth said afterwards. "I had something that was working, but I was hurting the rear tyres and ended up hurting the front tyres, too.

"I was hesitant to get off my line and it made my car too tight," he explained. "I needed to change my line, but I didn't have enough cushion to do it. He was always too close."

"When your team puts you in front, it's disappointing not to win," Kenseth added. "I just got beat by experience and a better driver at this track. I tried to change my line and got too tight at the end, but overall it was a great day.

"I have nothing to complain about," he summed up. "I'm not as happy as Jeff, but I'm happy to run second."

He might have been denied a victory at what had historically been one of his worst tracks to race at, but second place - just six hundredths of a second ahead of a resurgent Clint Bowyer at the line - put him ahead of Johnson who finished in fifth place just behind reigning champion Brad Keselowski. That three place difference, added to Kenseth's extra bonus point for leading the most laps (202), meant that Johnson's slender lead coming into this weekend's race had been wiped out and he and Kenseth were now dead level on points going into the final three races of the 2013 season.

Moreover, Gordon's victory at Martinsville had put fresh wind into the four-time champion's sails as well, boosting him up to third place in the standings 27 points adrift of the joint leaders, and just one point ahead of Kevin Harvick who finished in sixth place on Sunday to keep himself in with a shot at the title as well.

"Just like it's been - it's been a great battle with the #20 car, and the #24 is really showing that he wants to be a part of this deal, as well," said Johnson. "And there are some other guys back there kind of close. So, it's going to be a dogfight to the end - the way that I would want to go racing for a championship, and I know that's exactly what the fans want to see. We'll keep digging hard."

Losing ground on the leaders was Kyle Busch, who after running in the top ten for most of the race ended up falling to 15th by the line, meaning he falls 36 points off Johnson and Kenseth. Even so, that's still within the number of points available at a single race weekend (48) and so it's too soon to count the #18 out. The rest of the field - from Clint Bowyer, Dale Earnhardt Jr. and Greg Biffle on down - are almost certainly out of the running, although no one is yet mathematically completely out of the running, not even Kasey Kahne who is 124 points adrift.

Johnson did have one headache coming out of Martinsville, however. A run-in with Greg Biffle during the race in which the #48 had ripped off the rear bumper of the #16 left Biffle seeking out Johnson after the race to remonstrate with him, and the words used weren't always fit for a family audience.

"You tore my rear bumper off, you ******" yelled Biffle, to which Johnson responded by insisting he'd been inside the #16 when Biffle turned down on him. "You ******* ran into the back of me," Biffle replied. "You better watch it."

Johnson's offer to talk about the incident was shrugged off by Biffle, but tempers cooled off a little by the time both men spoke to the media.

"It takes a lot to get a rear bumper to come off," Biffle said. "I have got to look back and see what happened. He claims he was inside of me. It sure felt like he hit me from behind and rubbed it across."

"We were racing earlier in the day and he's upset about something," Johnson said for his own part. "We seemed to talk about it and kind of get through it, so we'll see how things go," he added. "Short-track racing, that's all - everybody gets good and heated."

"It was just Martinsville stuff," Biffle agreed. "Like he said, he didn't do it on purpose. But the fact of the matter is he got me hard enough to rip the bumper off."

It's unlikely to be an ongoing feud between the two - Jimmie Johnson is too wily when it comes to championship runs to saddle himself with distractions when he can least afford it - and especially not when Matt Kenseth has just proven himself a formidable opponent who can't be thrown off the scent by the usual ace up the #48's sleeve. It seems that Johnson will need some new tricks to be sure of winning his sixth title after all.

Full race results, interview with the winner and Sprint Cup Championship standings are available.