Simon Pagenaud boosted his hopes of a maiden Verizon IndyCar Series title by claiming pole position for Sunday's championship showdown at Sonoma Raceway.
Pagenaud headed up a Penske sweep of the top four positions in qualifying, breaking teammate and title rival Will Power's existing track record from 2015 before taking his seventh pole of the year with a lap of 1:16.2565. Power could only manage fourth place on the grid behind Helio Castroneves and Juan Pablo Montoya.
Pagenaud extended his lead over Power to 44 points after picking up the bonu points for pole, putting him in a strong position ahead of Sunday's race.
"It feels great. Most importantly up until now there was no thinking about the race, no thinking about the outcome. It was all about raw speed," Pagenaud said.
"We had good balance on the car. The first lap, put the red Firestone tyres on. I went on the radio and said, 'Wow, this is going to be good.' We were able to replicate the lap time every time.
"Unbelievable that we could actually replicate the lap time in the Firestone Fast Six with used tires. Certainly I did everything I could by challenging every high-speed corners that I could. I was on the edge, but it was a really good lap.
"Super proud of these guys. The guys on the No. 22 team, seven poles this season, four wins. No matter what happens tomorrow, it's been an incredible season."
2014 IndyCar champion Power admitted that his hopes of a second title now rest on an unpredictable race at Sonoma.
"That's all I could do in qualifying, that was everything I had and the car had," Power said. "It's a long race. I think it's going to be a race of degradation. It's going to be really interesting the way the tyres go.
"Last thing we need now is a straightforward race because Simon will be tough to beat if that's the case. Honestly, I need to win the race to win the championship, and he has to have a bad day."
Graham Rahal was the best non-Penske in fifth place for Rahal Letterman Lanigan Racing, while Ryan Hunter-Reay made good on Andretti's impressive practice pace to qualify sixth. Outgoing champion Scott Dixon will start from seventh at Sonoma ahead of Alexander Rossi and Sebastien Bourdais, while Josef Newgarden rounded out the top 10.
2016 GoPro Grand Prix of Sonoma – Starting Grid
1. (22) Simon Pagenaud, Chevrolet, 01:16.2565 (112.594)
2. (3) Helio Castroneves, Chevrolet, 01:16.4134 (112.362)
3. (2) Juan Pablo Montoya, Chevrolet, 01:16.5400 (112.177)
4. (12) Will Power, Chevrolet, 01:16.6659 (111.992)
5. (15) Graham Rahal, Honda, 01:16.7149 (111.921)
6. (28) Ryan Hunter-Reay, Honda, 01:16.9132 (111.632)
7. (9) Scott Dixon, Chevrolet, 01:16.5700 (112.133)
8. (98) Alexander Rossi, Honda, 01:16.5840 (112.112)
9. (11) Sebastien Bourdais, Chevrolet, 01:16.6115 (112.072)
10. (21) Josef Newgarden, Chevrolet, 01:16.8142 (111.776)
11. (7) Mikhail Aleshin, Honda, 01:16.8909 (111.665)
12. (83) Charlie Kimball, Chevrolet, 01:16.9627 (111.561)
13. (10) Tony Kanaan, Chevrolet, 01:16.9481 (111.582)
14. (27) Marco Andretti, Honda, 01:16.9288 (111.610)
15. (14) Takuma Sato, Honda, 01:16.9661 (111.556)
16. (26) Carlos Munoz, Honda, 01:17.0314 (111.461)
17. (41) Jack Hawksworth, Honda, 01:17.0823 (111.387)
18. (8) Max Chilton, Chevrolet, 01:17.1310 (111.317)
19. (20) Spencer Pigot, Chevrolet, 01:17.3052 (111.066)
20. (5) James Hinchcliffe, Honda, 01:17.1926 (111.228)
21. (18) Conor Daly, Honda, 01:17.6771 (110.535)
22. (19) RC Enerson, Honda, 01:17.3264 (111.036)