McLaren's Fernando Alonso topped the final practice ahead of 2019 Indianapolis 500 qualifying, where just six cars took part in the session.
Alonso, who admitted on Friday that he was worried about his prospects of qualifying for the 103rd running of the Indy 500 following the problems he has endured in the earlier practice sessions, set at best lap at 228mph.
The double Formula 1 world champion, produced a no-tow lap of 228.065mph in his McLaren-Chevrolet, although his speeds dropped off by over 1mph within two more laps.
This could be an issue for Alonso in qualifying because positions are set by the fastest average speed over four laps.
His running in final practice also took place in ideal conditions on a cool track, with much of it in shade.
During qualifying in the afternoon, track conditions are likely to be more difficult for the drivers, as ambient temperatures are expected to be much hotter.
Behind Alonso in final practice, were Jordan King in the third Rahal Letterman Lanigan Racing-Honda and Kyle Kaiser in a rebuilt Juncos Racing-Chevy following his crash on Friday.
Ben Hanley ended up fourth in the DragonSpeed- Chevrolet and Patricio O'Ward in the spare Carlin-Chevy was fifth.
The qualifying session will feature all 36 cars completing at least one four-lap run to set grid positions 10 through 30.
The participants for Sunday's Fast Nine shootout for pole and Sunday's Last Row competition (six cars fighting for the three back-row slots) will also be decided.