Will Power leads a Penske clean sweep of the top three in IndyCar qualifying at Sears Point

Power, who won at the California road course last year, set the benchmark with a 1m18.6017s effort that proved well beyond the reach of any of his rivals.

Helio Castroneves came closest, albeit almost 0.5s in arrears, while Ryan Briscoe was third fastest.

"We were just smart with our tyres in the first two rounds, and we knew we had to lay one down in the third round, and we did that," said Power after securing his sixth pole position of the season.

"It's important here - it's tough to pass - but a Penske 1-2-3 is very good. We've got two guys between us and the Target [Ganassi] cars, and that's what we need."

Championship leader Dario Franchitti will line up alongside Briscoe on the second row after failing to find the gains he needed from the softer 'red' tyres, with his Chip Ganassi Racing team-mate Scott Dixon right behind him in fifth.

Rookie Jamies Hinchcliffe rounded out the top six with a great performance in his Newman/Haas car.

Britain's Mike Conway was a strong seventh for Andretti Autosport ahead of Sebastien Bourdais (Dale Coyne), with Ernesto Viso (KV) and Ana Beatriz (Dreyer & Reinbold) rounding out the top 10.

Pos  Driver               Team               Time        Gap
 1.  Will Power           Penske             1m18.602s (Q4)
 2.  Helio Castroneves    Penske             1m19.092s (Q4) + 0.490s
 3.  Ryan Briscoe         Penske             1m19.111s (Q4) + 0.505s
 4.  Dario Franchitti     Ganassi            1m19.164s (Q4) + 0.545s
 5.  Scott Dixon          Ganassi            1m19.389s (Q4) + 0.788s
 6.  James Hinchcliffe    Newman/Haas        1m19.545s (Q4) + 0.853s
 7.  Mike Conway          Andretti           1m18.939s (Q3) + 0.337s
 8.  Sebastien Bourdais   Dale Coyne         1m18.971s (Q3) + 0.370s
 9.  Ernesto Viso         KV                 1m19.072s (Q3) + 0.471s
10.  Ana Beatriz          Dreyer & Reinbold  1m19.110s (Q3) + 0.508s
11.  Giorgio Pantano      Dreyer & Reinbold  1m19.241s (Q3) + 0.640s
12.  Alex Tagliani        Sam Schmidt        1m19.803s (Q3) + 1.202s
13.  Graham Rahal         Ganassi            1m19.331s (Q2) + 0.729s
14.  Marco Andretti       Andretti           1m19.378s (Q2) + 0.770s
15.  Martin Plowman       AFS/Sam Schmidt    1m19.379s (Q1) + 0.776s
16.  Takuma Sato          KV                 1m19.384s (Q1) + 0.719s
17.  James Jakes          (Dale Coyne)       1m19.474s (Q1) + 0.873s
18.  Oriol Servia         Newman/Haas        1m19.396s (Q1) + 0.739s
19.  Ryan Hunter-Reay     Andretti           1m19.640s (Q1) + 1.039s
20.  JR Hildebrand        Panther            1m19.465s (Q1) + 0.864s
21.  Tony Kanaan          KV                 1m19.727s (Q1) + 1.125s
22.  Simon Pagenaud       Dreyer & Reinbold  1m19.564s (Q1) + 0.962s
23.  Sebastian Saavedra   Conquest           1m19.752s (Q1) + 1.150s
24.  Ho-Pin Tung          Sam Schmidt Dragon 1m19.589s (Q1) + 0.988s
25.  Danica Patrick       Andretti           1m19.785s (Q1) + 1.184s
26.  Charlie Kimball      Ganassi            1m19.835s (Q1) + 1.233s
27.  Ed Carpenter         Sarah Fisher       1m20.627s (Q1) + 2.713s
28.  Vitor Meira          Foyt               1m20.121s (Q1) + 1.837s