Brad Keselowski finally caught a break.

Keselowski's good fortune came at the expense of continued bad luck to Kyle Busch, who failed to win Saturday's Heluva Good! 200 despite leading a race-high 108 of 200 laps at Dover International Speedway.

Keselowski took the lead for the first time on the next-to-last lap of the NASCAR Nationwide Series race after Logano ran into the back of Busch, his team-mate at Joe Gibbs Racing, moments after a restart on Lap 199.

The contact sent Busch up the concrete racing surface at the Monster Mile and gave Keselowski the opening he needed.

A day after failing to qualify for Sunday's Sprint Cup race, Keselowski made a winner of JR Motorsports owner Dale Earnhardt Jr. when he powered his #88 Chevrolet past Logano's #20 Toyota through turns one and two and crossed the finish line two laps later, .299 seconds ahead of the 19-year-old driver.

Clint Bowyer ran third behind Logano. Brian Vickers finished fourth, followed by Carl Edwards, who trimmed Busch's lead in the series standings to 40 points. Busch cut a tyre during the incident with Logano and finished 17th.

Paul Menard, Scott Speed, Jason Leffler, Jason Keller and rookie Justin Allgaier completed the top ten. Leffler posted his seventh straight top-ten of the season and remained third in the standings.

"We had a great car, we put ourselves in position to win, we needed a break, and we caught a break," said Keselowski, who won his third Nationwide race. "Don't feel guilty about it. Not one bit. I saw the 18 slow down and the 20 making a basic manoeuvre. I just saw a hole, went for the hole and I made it. I was there and ready for it, and it worked out."

Logano, who started from the pole and led 87 laps, took responsibility for the contact that cost his team-mate the race.

"At the end I just screwed up," Logano said. "That's what happened. I got behind Kyle on the restart. Finally I got a good restart - he'd been kicking my butt every restart, kicking my butt through the first corner. I was trying to stay right up on him. I wasn't going to make the move and dive down underneath him into the corner, because I figured he'd just blow my doors (off).

"So I wanted to stay with him through the first corner and try to make a move after that. I got right up on his bumper, and he went into (turn) one and let up earlier than I thought he was going to, and I got in the back of him. It was completely my fault. There was no room for error at where I positioned my car right behind him."

Busch, who did not speak to the media after the race, said on his team radio, "I would just point out that we took care of him (Logano) about ten times today. Could have wrecked him."