It is the first victory for the Penske Racing driver since last September at California Speedway and it came on a day when two-time Cup champion Tony Stewart dominated, only to see his hard luck continue and his winless string increase to 31 races.
"These guys made an awesome call," Busch said. "Sometimes you just don't win 'em the right way, I think we can honestly say that, but we had a lot of work and a lot of effort put in today and we'll take it."
Stewart held off a challenge from two-time reigning Cup champion Jimmie Johnson late in the 301-lap race and appeared on the way to his first victory since last August at Watkins Glen, N.Y., but Stewart and most of the other drivers who had been racing at the front of the pack did not have enough gas to get to the end.
On lap 271, Dale Earnhardt Jr., who had been in the top 10 all day, started toward pit road and was hit from behind by Jamie McMurray, who then spun into David Ragan, bringing out a caution.
Stewart and the rest of the front-runners pitted under the yellow flag, while Busch and seven other drivers who had pitted more recently than the leaders, stayed on track.
The race restarted on lap 279, but there was another crash on lap 280, with Clint Bowyer and rookie Sam Hornish Jr. crashing, then Juan Pablo Montoya slamming into series points leader Kyle Busch under the ensuing caution flag.
The rain that had been threatening for much of the afternoon began falling moments later and, moments after the cars were red-flagged onto pit lane just before completing lap 285, NASCAR called the race, leaving Busch on top, ahead of Michael Waltrip, J.J. Yeley, Martin Truex Jr., Elliott Sadler, Reed Sorenson and Casey Mears, all of whom had stayed on track during the previous caution.
"It's just been the oddest year I've ever seen for this race team," a disappointed Stewart said. "It's just frustrating. There isn't anybody that's going to tell you any different than that. There's nothing you can do. If there was something we could do about it we'd change it."