Keselowski had to hold off a final charge from Kevin Harvick, but after Harvick closed within a few car lengths, Keselowski kept him at bay and slightly expanded his margin in the final laps to win the three-way dual among some of NASCAR's most aggressive and daring drivers.
"You're racing the best and you know if you make a mistake, they're going to beat you," Keselowski said.
The victory was the 21st of Keselowski's career in the series and second on the 0.75-mile oval.
"We had a fast car at the end," Keselowski said. "It was just a matter of putting it in the right position."
Harvick, who led four times for a race-high 96 laps, was followed across the finish line by Busch, whose streak of three consecutive victories in the series came to an end. Brian Vickers was fourth, followed by Regan Smith.
"All in all, it was a fun night," Harvick said. "He just had a better car for the short runs."
The duel with Busch and Keselowski seemed as enjoyable to be part of as it was to watch.
"On any night it's fun when you can race like that," Harvick said.
"It was good. Certainly there were some tense moments there," he said. "You're fighting for everything you can get."
The race finished with a skirmish on pit road between the teams of season-long rivals Brian Scott and Nelson Piquet Jr., with Scott saying his Richard Childress Racing team was upset because Turner Scott Motorsports' Piquet ran him into the wall while fighting for 15th place late in the race.
"When I went to talk to him, he just pushed and shoved me and then kicked me below the belt," Scott said. "It's just a chicken move."
Richard Childress Racing crew members Michael A. Scearce, 50, and Thomas F. Costello, 35, were arrested and charged with misdemeanor assault and later released.
Multiple reports late Friday night said a second altercation stemming from the first occurred in the driver/owner motorhome lot and that two adult males were in police custody. Reports said one of two adult male victims suffered a shoulder injury.
Richard Childress Racing confirmed members of its team were involved, releasing a statement that read: "We are aware an incident took place outside of the track's infield following Friday night's NASCAR Nationwide Series race at Richmond International Raceway involving members of our team and others from another team. We are cooperating with the local authorities in this matter."
Sam Hornish Jr., the points leader and pole sitter, was dominant early. He led 83 laps, but his car faded at the end of a long green-flag run and he never contended again. He wound up seventh, but retained the points lead by one over Smith.
Ryan Reed, making his series debut, raced in the top 10 for part of the race and faded late, finishing 16th.
The Associated Press contributed to this report.