5:32 PM PT -- Keanu Reeves lost control of his car in his pro auto racing debut at the Indianapolis Motor Speedway, narrowly avoiding a crash.

Keanu was coming out of Turn 9 when his car spun into the grass ... though he was able to avoid smashing into the wall.

Video shows Keanu spinning out, and after a brief pause he gets back on the track and finishes out the race.

Keanu was uninjured and he qualified 31st out of 35 cars. Next up for Keanu is another race on Sunday.

Keanu Reeves sure knows a lot more than kung fu ... and he's gearin' up to prove it Saturday as he readied to make his professional auto racing debut at the Indianapolis Motor Speedway.

In exclusive pictures and video obtained by TMZ ... Keanu can be seen preparing for practice runs Saturday morning behind the wheel of the No. 92 Eagles Canyon Racing Toyota GR86.

The GR Cup Series races happening over the weekend are a part of the Indianapolis 8-hour event ... but separate from the endurance race.

This is far from KR's first (race) rodeo ... the dude has had some serious experience both driving in his high-octane Hollywood action films -- most recently "John Wick 4" -- and even in the Toyota Grand Prix of Long Beach in the celebrity race!