The crash involved at least a dozen cars, and wreckage was spread across the track, forcing NASCAR officials to bring out the red flag and causing a 20-minute delay as the track was cleared.
No one was hurt in the incident.
The crash began when Tony Stewart tapped the left side of Landon Cassill's car, causing the Toyota to spin up the track toward the wall. Almost at the same moment, David Ragan bumped Stewart, causing both cars to spin and setting off a huge pileup behind them as drivers attempted to avoid all the spinning metal.
Jimmie Johnson was the eventual victor, winning for the seventh time at Dover, which ties him with both Bobby Allison and Richard Petty.
Check out video of the wreck below.