Ryan Hunter-Reay topped the final warm-up session ahead of IZOD IndyCar Series race at Sonoma.
The Andretti Autosport driver went to the top in the final moments with a best lap of 1m19.0645s, besting previous pacesetter Mike Conway by 0.1404sec. Oriol Servia, Tony Kanaan and Simon Pagenaud rounded out the top five.
Polesitter Will Power, who has elected to start the race from the left side of the track, finished the morning with the seventh-fastest time, just behind Scott Dixon.
Ganassi's Charlie Kimball was responsible for a brief red flag for debris when he hit the tires shortly after the session began, although the American was able to continue running after a visit to the pits for a new nose.