DAYTONA BEACH, Fla. — Tony Stewart's freaky season of bad luck took another turn when the two-time NASCAR champion fell ill during tonight's race at Daytona International Raceway.

Stewert started the Coke Zero 400 and ran as high as third, but gave way to J.J. Yeley on lap 72. Stewart got out of his No. 20 Toyota, sat down in his pit stall and wiped beads of sweat off his face with a towel while drinking water.

NASCAR officials said crew chief Greg Zipadelli informed them Stewart had been up the night before with some sort of virus.

Yeley, who spent three seasons as Stewart's teammate at JGR, failed to qualify for Saturday's race. He now drives for Hall of Fame Racing, an affiliate of JGR.

This is the kind of bizarre occurrences that have plagued Stewart all season.

He had his heart broken on the last lap of the Daytona 500, when a victory in NASCAR's biggest race was snatched away from him by winner Ryan Newman. It was an agonizing defeat, but he didn't let it linger. He had no hard feelings when he returned to Daytona this week.

"My buddy that came with me from home, we were talking about how many wins we actually have here," Stewart said. "We've got a lot of wins and this is a race that has been really good for us. I'm looking forward to it actually."

Stewart had good reason to be excited for Saturday night. He won this 400-mile race in 2005 and 2006. The first year he led all but nine of the 160 laps, and led half of the race the next season. He might have made it three straight, too, but wrecked with teammate Denny Hamlin while they were running first and second in last year's race.

All said, he has won 12 races here and had a dominant car in February when he won the Nationwide Series race, finished second in two exhibitions, then was leading the 500 with a half-lap to go when Newman snatched the win away from him.

In hindsight, it was the first sign of things to come. He has had strong cars all year, only to lose his shot at a win in freak fashions. Accidents, broken parts, blown tires and even the weather have plagued Stewart and stretched his winless streak to a career-worst 31 races.

Stewart has not been to Victory Lane since winning on the road course at Watkins Glen last August.

"I'm scared to get in cars, planes, everything," Stewart said. "I'm scared to walk, open doors without looking before I walk through — it's the oddest year I think I've ever seen. I've never seen this team and even in my career — I've never seen us have a string of bad luck like this.

"It comes in waves. We've had short periods of bad luck, but we've never had bad luck like we've had this year."

Despite the difficulties, Stewart is still having a decent season. He's ninth in the points, has eight top-10s, led 520 laps and dominated several races — leading 267 of 506 at Bristol and 132 of 284 last week at New Hampshire. But he gave up the lead last Sunday on a late pit stop, when crew chief Greg Zipadelli decided to take two tires instead of just fuel, then was denied a chance to charge back to the front when the race was shortened for rain.

The move exposed Zipadelli to criticism, but Stewart defended his longtime crew chief.

"I wouldn't want to have that job," he said. "I wouldn't want to have that responsibility. It just frustrates you as a driver that you've got a crew chief that's won two championships and 30-plus races with you, that people think they are a lot smarter and they're not."

A win Saturday night could help Stewart silence the critics and jump-start his season. He's had stretches where his Joe Gibbs Racing team could do nothing wrong, and this run of bad luck has forced him to reflect on the ups and downs of his 10-year NASCAR career.

"It could be a lot worse. There's guys that have had a lot worse seasons than we've had, but this is a terrible year for us and our team," Stewart said. "I think that is a compliment to how good of success this team and this organization has had. I don't know how long it's going to last — hopefully it's not much longer, I'm afraid I'm going to be bald by the time it's done.

"It just reminds you of the stretches that you've had that everything goes right. It reminds you of how hard those are to have. And when you do get a string like that how much to appreciate it versus days that you think you should've won and you ran and being frustrated about it. It's like, 'Man, I'll take a third some of these days right now.' I think it helps put it in perspective even though it's frustrating."