At the Indianapolis 500, Guerrero entered as a favorite alongside Mario Andretti and Bobby Rahal. Guerrero qualified in 5th place and ran at the front of the field all race. On lap 130, Tony Bettenhausen, Jr. lost a wheel and it was punted into the air by Guerrero's car. The wheel ended up landing in the top row of the grandstands in the south chute (between turns 3 and 4) and hit spectator Lyle Kurtenbach, who was killed instantly. When Andretti suffered electrical issues on lap 177, Guerrero took the lead and made his final pit stop on lap 182, as he was nearly one lap ahead of 2nd place Al Unser, Sr. After the pit stop, Guerrero stalled his engine, then stalled it again after his pit crew managed to push start it. Guerrero's brake master cylinder and clutch had been damaged in the incident with Bettenhausen. During this time, Guerrero lost one lap to Unser, who was now leading, but he would unlap himself with nine laps to go. Despite a late race caution for Andretti, Guerrero would lose the race to Unser, who won a record-tying fourth Indianapolis 500.