Classic Rewind continues its look at the 1987 Indy car season with the Indianapolis 500, the race where Al Unser scored an underdog win and became a four-time Indy 500 winner.

In honor of the month of May in Indianapolis, Classic Rewind will be bringing vintage broadcasts of the Indianapolis 500. 

This week, we resume our look at the 1987 season and travel to Round 3, the Indianapolis 500, a race that saw Al Unser become the second man to win the "Greatest Spectacle in Racing."

Unser arrived at Indianapolis without a ride, but when Danny Ongais was injured in a practice crash, Roger Penske called upon the veteran driver to pilot the No. 25 Cummins/Holser Turbo March Cosworth. The race looked to belong to Mario Andretti, who had the dominant car through the month, and led most of the race before sustaining mechanical issues with 23 laps to go.

Five laps later, Unser took the lead and held off Phoenix race winner Roberto Guerrero for the win.