In August 1965, at the Milwaukee 200-mile (320 km) Championship Car race, Foyt's rear-engined Lotus pavement car was not at the track. So Foyt unloaded the Offenhauser-engined dirt track car he had won the 100-mile (160 km) race with at Springfield the previous day. He sprayed the mud off the car, installed pavement tires and a set-up for the one mile (1.6 km) oval. Foyt received permission to take two extra warm up laps during qualifying, as he had no time for practice. He then qualified the car on the pole, led the race for 18 out of 200 laps but then had to stop for a new rear tire, and finished second to Gordon Johncock, driving a rear-engined Gerhardt-Offy Indy car.
In January 1965, Foyt qualified and ran in the front of the pack most of the day with Dan Gurney and Parnelli Jones in the Motor Trend 500 at Riverside. Parnelli retired with mechanical issues, leaving Gurney and Foyt to contest the lead. Late in the race, dueling with Gurney, Foyt spun. His car refired, and he charged through the field in an attempt to regain lost positions. After running hard to catch leader Gurney, Foyt's brakes failed entering turn nine at the end of Riverside's mile-long, downhill back straight. Foyt turned the car into the infield at more than 100 mph, was launched off an embankment, dropped into a lower area and slammed into a sandy embankment, violently tumbling end-over-end several times. The track doctor at Riverside International Raceway pronounced Foyt dead at the scene of the severe crash, but fellow driver Parnelli Jones revived him after seeing movement. Foyt suffered severe chest injuries, a broken back, and a fractured ankle. Footage of his flipping No. 00 Ford, owned by Holman Moody, is featured in the final scene of the movie Red Line 7000.