Marco's turn of speed proved brief and then it was Sebastian Bourdais' turn to shine under the floodlights with a surge into the front ahead of Castroneves. The driver really impressing at this stage was Carlos Munoz, who after winning the Indy Lights race earlier in the day seemed to be making a bee-line for the front with a unique capacity to run the low line. In the end, it ended in tears: the young rookie pushed his luck a little too far and he spun out in turn 2 on lap 101 while in third place, nearly collecting Marco Andretti on the way and forcing Dixon to duck down low to avoid getting caught up in the incident.
Everyone pitted under the caution, with Castroneves emerging from pit lane ahead of Bourdais, Kanaan, Hunter-Reay, Allmendinger and Power as once again the yellows helped Chevrolet maximise their power advantage and minimise their fuel conservation deficit to the Honda runners. Dixon fell back to 12th place for the green flag on lap 109, partly as a result of the team wanting to check the back of the #9 after that earlier rear contact with Munoz at the previous restart.
The green lasted barely two laps before Justin Wilson got caught out while battling with Graham Rahal by a prominent seam in the track surface in turn 2, the car wobbling and Wilson finally unable to save it. Oriol Servia went high to avoid the developing accident, only to get flattened against the outside wall by Josef Newgarden; Wilson's spinning car was also collected by Tristan Vautier, while a scarily large chunk of debris also hit the Rahal Letterman Lanigan car of James Jakes who had been unsighted by all the wheel smoke from the incident. Simona de Silvestro ended up running through the infield to avoid the fall-out, but avoided the worst of it and lived to fight another day.
"I saw Justin getting loose and I thought I'd be able to avoid it, and I did. But Josef (Newgarden) was there as well and collected me, but it was just one of those things where it was too many of us in the same real estate," said Servià. "Nobody did anything wrong because there was nowhere to go. But it was a shame because we were dialled in to be strong at the end of the race. It was tough out there tonight – everybody was sliding around, so it was one of those nights where you wanted to get to the last pit stop and then start racing. Everybody was being patient and driving really smart, but things can always go wrong."
There was a lengthy pause for a clean-up and also to remove Wilson to an ambulance on a stretcher for transport to a local hospital for a pelvis injury and for further tests and evaluation on his back, but otherwise awake and alert. There were few cars making a move to pit lane with the exception being Will Power who was having issues with his helmet visor tear-offs that put him to the back of the lead lap, and Hunter-Reay who had to surrender second place because of a puncture from the debris out on the track.
That left Castroneves in charge for the restart on lap 127 with Bourdais, Tagliani, Kanaan and Andretti, with Pagenaud - who had been forced to make an unscheduled early pit stop after his first set of tyres were inflated to the wrong pressure - now back in-sync and up into sixth place ahead of Dixon, whose championship ambitions had actually been helped by all the attrition and further assisted when his stand-in team mate Tagliani took to the front to deprive Castroneves of the crucial position. In fact the cooler conditions of the full night time were not proving helpful to Castroneves, who slipped to sixth even as Dixon surged into the top three behind Tagliani and Andretti.
While his team mate continued to struggle during this stint, his Penske team mate Will Power flew to the front on lap 134 and surged away from Dixon, Tagliani, Andretti and Bourdais. Also on the prowl was last year's winner Ed Carpenter who had worked his way into the top six, but emphatically out of the hunt was Takuma Sato who ended up parked on pit lane on lap 144 with overheating issues.
Lap 153 saw an outbreak of fuel stops for Carpenter, Andretti and Castroneves, with Dixon, Kanaan and Bourdais in next time in with a long hold for the #7 with a hold-up on the front left. Everyone was chasing the changing conditions as nightime wore on, with a build-up of debris in the radiators causing many of the teams to worry about climbing temperatures in the cars. Power and Hunter-Reay were the last to come in, both slightly off-sync having pitted under the previous caution and making something close to 38 laps apiece on their latest tank of fuel, compared with 42 for the Honda-powered Charlie Kimball who was the latest to stop in the sequence.
Power was back in charge after the cycle completed with Dixon into second ahead of Tagliani and Castroneves once again back on the pace in fourth despite visibility problems with his visor after the recent round of set-up changes put him ahead of Hunter-Reay and Pagenaud for a settled period of running for the leaders as they girded themselves for the finish. Andretti Autosport signalled the start of the penultimate round of pit stops of the season by calling in Hunter-Reay and Macro Andretti on lap 186, after which a number of other cars trickled through pit lane.
Dixon had been in the process of making his own stop when out on track AJ Allmendinger hit the wall in turn 4 on lap 191, apparently as the result of having to take evasive action to avoid hitting Ed Carpenter who had been slowing to come on to pit road after running out of fuel. Power and Kimball were the two cars left out and having to wait for pit road to reopen, which promoted Dixon into the lead of the race for the first time of the night for the restart on lap 199.