The bumping sent Stewart plunging to the back of the pack, but he rebounded in the closing laps to finish fifth.
Stewart's aggressive move on Kenseth earned him a penalty under the stricter rough-driving policy Stewart himself had lobbied officials for earlier in the week.
''Tony went out and said all that stuff early in the week,'' Kenseth said. ''If he's worried about people's lives and he's going to wreck somebody at 190 mph, that's tough.''
Said Stewart: ''He has no room to complain. He started it and I finished it.''
Stewart might have finished things with Kenseth, but he wasn't quite finished in the race. With seven laps to go, his scrape with Kyle Busch on the backstretch nearly sent Stewart spinning out and earned Busch a NASCAR penalty.
Heading into the race, Stewart's safety crusade had been the most prominent story line of Daytona Speedweeks.
After witnessing drivers' aggressive bump-drafting techniques in an exhibition race last Sunday, he took his complaints to reporters and NASCAR officials.
In response, officials announced that they would police aggressive driving more closely. Little did he know he would be the new policy's most prominent victim.
Stewart's crew chief, Greg Zipadelli, didn't dispute the penalty.
''That's what they saw, and we took our lumps, came in and went back out,'' Zipadelli said. ''I mean, it is what it is. They warned us, they did it to other people, so it's not a big deal. As long as they stay consistent and keep doing it that way, I'm all right with it.''
Kenseth clearly was furious with Stewart after the accident, and the normally low-key driver's anger earned him a penalty of his own.
''Tony took me out intentionally,'' Kenseth said. ''There's no two ways about that. He was mad because earlier in the race when I passed him he got loose, which I didn't think I did anything wrong.''
Said Stewart: ''Matt always thinks that. I guess Matt didn't think anything when he got me sideways over in [Turn] 2 either.''
Despite warnings from NASCAR officials to both drivers to calm down, Kenseth zoomed around Stewart and swerved toward him after a pit stop.
It was unclear whether Kenseth's car actually made contact with Stewart's - Kenseth radioed his crew claiming he didn't hit Stewart - but the move was enough for NASCAR to call a penalty on Kenseth.
Stewart also tangled with Gordon early in the race, but was not penalized for that confrontation.
Stewart was shuffled out of the race lead on lap 47 and was trying to keep from losing several spots when he tried to get back in line with the rest of the field and tapped Gordon from behind.
Both cars brushed the wall, and Gordon made an impressive save to keep his car from spinning out.
''I am going to take part blame for that,'' Gordon said. ''I think Tony should take part of it as well. . . . I think it could have been avoided by both of us. It was an unfortunate incident that hurt us both a lot.''