On lap 16, Tony Stewart attempted to change lanes and make a move on race leader Matt Kenseth. While he wasn’t cleared by his spotter, Stewart chose to shift down low which resulted in his left rear corner making contact with the right front of Marcos Ambrose. Stewart’s car got out of shape, made contact with the apron and sent a shower of sparks over several cars that were pursuing him. Jimmie Johnson checked up in the high line, which caused Denny Hamlin to make contact with the five-time champ, turning him down in front of the oncoming pack and ultimately taking out one-third of the field. The accident eliminated defending champion Kyle Busch, two-time Unlimited champion Jeff Gordon, 2006 winner Denny Hamlin and 1999 winner Mark Martin. Just like that, the field was reduced by one-third, many contenders sat idle in the garage and the drafting – along with the racing – became a shell of its former self.