Busch just missed a tripleheader sweep on the one-mile concrete track. He was in position to win the Trucks Series race on Friday but ran out of gas at the end.
He easily won Saturday’s second-tier series race and raced about 800 miles in three days.
On Sunday, Busch swapped the lead with Jimmie Johnson throughout most of the 400-mile race. Johnson, the four-time defending Cup champion, was hit with a late penalty for speeding on pit road.
Johnson, who won both Dover races last year, finished 16th after having the dominant car most of the race. Johnson led 225 laps to Busch’s 131.
“I ran my guts out trying to pass him,” Johnson said. “It’s unfortunate we didn’t have a chance there at the end.”
Jeff Burton was second and Matt Kenseth third. Denny Hamlin and David Reutimann rounded out the top five.
Busch won his second race of the season and moved into second place in the standings behind seventh-place finisher Kevin Harvick.
Joe Gibbs Racing has been putting heat on Johnson’s four-year reign atop the standings. JGR drivers Busch and Hamlin have been two of the hottest drivers over Johnson’s seven-race winless stretch and expect to contend for the title over the final 10 races.
“We’re just getting started,” owner Joe Gibbs said.
Busch became the second driver to win the Cup and Nationwide races in the same weekend at Dover.
Harry Gant did it in September 1991.
“We weren’t the best at the beginning, but we were definitely a top-four car today,” Busch said. “Awesome stops on pit road. I think they won the race today.”
Johnson led eight times and Busch six as two of the elite drivers in the sport engaged in back-and-fourth action at various times of the race.
Busch overcame early radio issues in the No. 18 Toyota. He couldn’t hear his crew and told them to stand on the wall and wave if they could hear him. The crew waved back.
When Johnson was hit for speeding, team members high-fived and briefly celebrated in the pits.