British Touring Car Championship leader Ash Sutton admitted he had to contend with a bout of food poisoning on his way to qualifying sixth for today's first race at Knockhill.

Along with carrying the full complement of success ballast, Sutton, understandably, said he felt a lack of energy, but still battled to out-qualify his nearest title rivals Tom Ingram and Dan Rowbottom.

Sutton's run to P6 didn't come without issue after his Infiniti Q50 slipped off the track briefly at McIntyres corner halfway through the 30-minute shootout.

The reigning two-time champion carries a slender five-point lead ahead of Ingram, with Rowbottom trailing a further seven-points back in third.

"We’ve not really had a true reading today [Saturday]," Sutton told Crash.net. "I’ve felt a bit under the weather. Car wise, we never had the right tyres on and we didn’t look strong at all in FP1 and FP2.

"P6 I was happy with. I left a little bit on the table. But looking at the times a few others did as well. I just need a good nights sleep for Sunday.

"It was just a lack of energy in me. Those little moments I always tend to gather up just got the better of me. I’ll put that down to the food poisoning!"

Crucially, Sutton will start three places higher than the ninth placed Hyundai of Ingram, while Rowbottom faces an uphill task from 19th on the grid.

"It hurts [carrying the ballast]. When you look at Colin [Turkington], he’s nearly 40 kilos lighter and we’re only a couple of tenths away. The pace is strong in the car," the Laser Tools Racing driver continued.

"We’re ahead of Tom and Dan. So in terms of the championship, we’re in a good place.

"We can try and claw something back in race two with a little bit less weight on. Everyone around us will gain more weight. That’s the key bit. It won’t affect us too much but everyone else gains the weight. So fingers crossed that plays into our hand for race two."