AP photo by Paul Sancya / Kevin Harvick (4) races past Brad Keselowski during Saturday's NASCAR Cup Series race at Michigan International Speedway. Harvick won the race for this fifth victory this season, and Keselowski finished second at his home track.

BROOKLYN, Mich. — Kevin Harvick forced his way past the reigning NASCAR Cup Series champion, then fended off another former champ who was trying to seize an elusive win on the top circuit at his home track.

It takes a lot to beat Harvick these days — especially in Michigan.

Harvick raced to his fifth win of the season, overcoming Kyle Busch and then outlasting Brad Keselowski in overtime Saturday at Michigan International Speedway, where the Cup Series will race again Sunday. Harvick now has four victories at Michigan, including three in the past three years. The 44-year-old Stewart-Haas Racing driver been a big part of what is now a five-race winning streak for Ford at the Cup level at the 2-mile oval.

"Just got challenged by a whole bunch of restarts at the end that made it kind of crazy," said Harvick, the 2014 Cup Series champ who strengthened his position as the points standings leader. "But in the end it was a great day for us. Everybody did a great job, called a great race, and we capitalized on a fast car and put it in victory lane."

Keselowski was denied again in his home state. Although he has won NASCAR national series events at the track, none of his 33 Cup Series victories are at Michigan. The 36-year-old driver who won the 2012 season title received a contract extension from Team Penske this past Monday, a day after taking the checkered flag at New Hampshire Motor Speedway for his third win of the year.

However, it would have been a tall order to overcome Harvick's dominant No. 4 car on Saturday, when he also won the race's first two stages.

"At no time did I think us or anybody else was better than the 4," Keselowski said.

Joe Gibbs Racing's Martin Truex Jr. finished third, followed by Penske's Ryan Blaney and JGR's Busch, who remained winless this year with five races left in the regular season. It was the eighth straight top-five finish for Harvick, who has now matched JGR driver Denny Hamlin's series-leading total of five victories this year.

For the first two stages, the only yellow flags were for a competition caution and the stage endings. Then there were six cautions in the final stage and even a brief red flag for track cleaning.

The race, normally a 200-lap, 400-mile affair, was scheduled for 156 laps this time. It went to overtime after Christopher Bell made contact with Austin Dillon to bring out the final caution.

Starting this weekend, NASCAR is incorporating the "choose rule" into the restart procedure for all national series races except those held on road courses and superspeedways. As drivers approach a designated spot, they must commit to the inside or outside lane for the restart.

"I think it definitely gave some guys a chance that were kind of buried eighth or ninth," Harvick said. "You can take a chance and gain some track position. So I thought it went well and did exactly what everybody thought it would do."

On the final restart, both Harvick and Hendrick Motorsports' Chase Elliott picked the outside, while Keselowski and Hamlin went inside. Harvick and Keselowski raced side by side for a bit, but Harvick had a clear lead out of the fourth turn then held on for another lap to win.

Keselowski reviewed video to see if he could have done anything different in hindsight.

"I had like three ideas," he said, "and I watched the replay, and none of them would have worked."

Harvick won for the 54th time on NASCAR's top circuit, pulling even with Lee Petty for 11th on the career list. He's one victory behind Rusty Wallace and two behind Busch.

For a brief moment, Busch was in front after one of the late restarts, but Harvick came up on the inside of him and Busch's car became loose and fell back. At first, it looked as if there might have been very slight contact between the cars.

"I didn't know if I hit him or not, but I saw the video and didn't touch him. I must have packed a bunch of air on his left rear," Harvick said. "I knew I needed to be right there. You have to take the chance when you have it, and I needed that side draft down the front straightaway. I got within like an inch, it looked like on the video."

Busch managed to finish in the top five despite that incident.

"I don't know whether he hit me or just air," he said. "It was close enough that it disturbed my car obviously and made me have to get out of it real bad."