Danny Sullivan won the Indy 500, in dramatic fashion, a race that became known as the "Spin and Win."

Al Unser Sr. took Mears' full-time seat at Penske Racing as a substitute for the season.

At the Pocono 500, Rick Mears triumphantly returned to victory lane after his leg injuries.

Meanwhile, Bobby Rahal was making a championship run of his own, winning 3 out of 4 races, and four poles in a row during a stretch in September–October.

Unser Sr. afterwards expressed some regret about snatching the championship title from his son, but felt it was his responsibility to his own team and his own sponsors to race to his ability all the way to the end.

Leader Johnny Rutherford was not informed, and second place Pancho Carter accelerated past him and beat him to the finish line.

In the Sanair race (Molson Indy 300), Roberto Guerrero had a strong lead until he lost control and spun.

Later in the race Jacques Villeneuve Sr. collided with leader Bobby Rahal in attempt to challenge for the lead, taking both out.

The race finished under a yellow flag, but the safety car entered pit lane on the final lap, and thinking there would be a final restart, Pancho Carter passed Johnny Rutherford after the safety car entered pit lane and before the finish line.

CART initially declared Carter the winner, but an appeals panel later overturned the decision and confirmed Rutherford's victory.