The victory was the 23rd for Keselowski, the 2012 Monster Energy NASCAR Cup Series champion, and his second in the first six races of this season. It made him just the eighth active driver with a victory in the top series on NASCAR's oldest and shortest oval.
Keselowski and Busch swapped the lead several times during a green flag run that began with 64 laps to go.
Keselowski had the lead coming out of a caution, but Busch quickly slipped underneath him to go back in front. Keselowski stalked him for several laps, the nose of his Ford inches from the rear bumper of Busch's Toyota.
When he finally got around Busch again, he gradually pulled away, opening a lead of nearly two seconds that helped him when he also had to navigate around lapped traffic.