Kyle Busch finished seventh in the Southern 500 and maintained his lead in the Cup points standings.
Kevin Harvick remains second in the standings on the strength of his fourth-place finish.
Martin Truex Jr. finished 11th – his fourth result outside the top 10 in the last five races – but maintained third position in the standings.
Keselowski more than doubled his playoff points bonus from four to nine.
Denny Hamlin finished 10th in the race and locked the No. 11 team into the playoffs.
Aric Almirola ended the night 12th in the standings and is also locked into the playoffs.