Simon Pagenaud topped the times in an extraordinarily tight second IndyCar practice session at Long Beach, where the top 19 cars were covered by less than a second.
Pagenaud took his place at the top of the sheets when he posted a 1m09.1488s lap with nine minutes left on the clock.
At that point he was 0.5 seconds clear of the rest of the pack, but compatriot Sebastien Bourdais came close to making the spot his own just a few minutes later.
His time fell short by just 0.012s, but it was good enough to secure a French lock-out of the top two places.
"The team has done a good job over the winter of helping the car on the kerbs and bumps," Pagenaud said.
"I'm really confident that we have a good car this weekend."
Rookie Jack Hawksworth was third-fastest and said that it was an encouraging sign for the next two days.
"The difference between here and [the last race] at St Pete is that this weekend we've rolled off the truck a bit stronger," he said. "At St Pete we were chasing it a bit right through the weekend and only got it dialed in when it mattered.
"I'm much more comfortable with the car this weekend, and I think we've got a bit more potential. I'm excited."
Rounding out the top five were last year's Long Beach winner Takuma Sato and Will Power, while Josef Newgarden repeated his solid form from the morning session by coming in sixth.
Juan Pablo Montoya managed to make it into the top 10 for the first time since returning to IndyCar, the Colombian finishing the afternoon with the ninth-best time.
Pos Driver Team/Engine Time Gap Laps 1. Simon Pagenaud Schmidt/Honda 1m09.1488s 18 2. Sebastien Bourdais KV/Chevy 1m09.1608s +0.0120s 19 3. Jack Hawksworth Herta/Honda 1m09.4409s +0.2921s 19 4. Takuma Sato Foyt/Honda 1m09.4524s +0.3036s 19 5. Will Power Penske/Chevy 1m09.4980s +0.3492s 19 6. Josef Newgarden Fisher/Honda 1m09.5356s +0.3868s 19 7. Ryan Briscoe Ganassi/Chevy 1m09.6173s +0.4685s 17 8. Justin Wilson Coyne/Honda 1m09.6537s +0.5049s 17 9. Juan Pablo Montoya Penske/Chevy 1m09.6987s +0.5499s 17 10. Ryan Hunter-Reay Andretti/Honda 1m09.7242s +0.5754s 16 11. Scott Dixon Ganassi/Chevy 1m09.7976s +0.6488s 20 12. James Hinchcliffe Andretti/Honda 1m09.8086s +0.6598s 20 13. Carlos Munoz Andretti/Honda 1m09.8158s +0.6670s 21 14. Mike Conway Carpenter/Chevy 1m09.8510s +0.7022s 24 15. Marco Andretti Andretti/Honda 1m09.8761s +0.7273s 19 16. Tony Kanaan Ganassi/Chevy 1m09.9799s +0.8311s 17 17. Oriol Servia Rahal/Honda 1m09.9926s +0.8438s 16 18. Mikhail Aleshin Schmidt/Honda 1m09.9968s +0.8480s 21 19. Helio Castroneves Penske/Chevy 1m10.0865s +0.9377s 19 20. Carlos Huertas Coyne/Honda 1m10.1914s +1.0426s 24 21. Graham rahal Rahal/Honda 1m10.2469s +1.0981s 21 22. Charlie Kimball Ganassi/Chevy 1m10.2478s +1.0990s 19 23. Sebastian Saavedra KV/Chevy 1m10.5842s +1.4354s 18