Penske's part-time star Will Power claimed his first IndyCar Series victory with a dominant performance at Edmonton.
The team could not quite replicate the one-two-three formation it had achieved in qualifying, but Power's team-mate Helio Castroneves did come through to second, ahead of Scott Dixon (Ganassi) and Ryan Briscoe in the third Penske entry.
Power was in control of the race from the outset, calmly pulling away from Briscoe and Castroneves in the early laps, as they left the chasing Ganassi duo in their wake as well.
Bar Castroneves vaulting Briscoe in the first stops, there was no change in the front pack until Power encountered traffic at half-distance.
The Australian spent lap after lap following Andretti Green duo Danica Patrick and Marco Andretti, and as he was delayed, Castroneves, Briscoe and Dixon closed right in to make a four-car lead train.
But once clear of the backmarkers, Power simply strolled away again, leaving his team-mates to fight among themselves.
Dixon ran longer than the Penske drivers at the last stop and vaulted up to second, but it would be shortlived.
Briscoe was immediately all over the Ganassi car as it tried to warm its tyres, and he crept through when Dixon went very slightly wide.
Things went wrong for Briscoe soon after though, as he lost places to be Dixon and Castroneves after brushing the Turn 10 wall and suspecting he had damaged his car.
But Castroneves restored Penske's one-two soon after by brilliantly diving past Dixon as they tried to thread a path through traffic.
He then inched away, leaving Dixon to successfully fend off the resurgent Briscoe, who was pushing hard to get around the reigning champion when Tomas Scheckter - already many laps down after earlier problems - crashed and caused the race to finish under its only yellow.
Dixon's third place allowed him to return to the points lead at the expense of team-mate Dario Franchitti, who took a low-key fifth.
Canadian superstar Paul Tracy - in what could have been his final 2009 IndyCar appearance - charged from ninth to sixth on the first lap, hitting KV team-mate Mario Moraes along the way, and then stayed there for the duration, resisting pressure from Graham Rahal (Newman/Haas/Lanigan) in the first half of the race before pulling away later on.
Justin Wilson (Dale Coyne Racing) came through to beat his Newman/Haas/Lanigan replacement Robert Doornbos to eighth. Doornbos still boosted his rookie title prospects, with pre-race contest leader Raphael Matos' day ruined by a first corner tangle with Mike Conway. Both eventually rejoined after repairs, as did Ryan Hunter-Reay after spinning into the wall and wiping off his rear wing. Prior to that, the Foyt driver had charged from 21st to 11th.
Andretti completed the top ten on another poor day for AGR. His team-mate Tony Kanaan had been set to finish at least ninth for the team before an apparent fuel rig problem caused a dramatic fuel spill and fire at his first pitstop. The former champion escaped with minor burns.
Pos Driver Team Time/Gap 1. Will Power Penske 1h42m42.3773s 2. Helio Castroneves Penske + 1.0936s 3. Scott Dixon Ganassi + 1.3213s 4. Ryan Briscoe Penske + 1.8266s 5. Dario Franchitti Ganassi + 4.4652s 6. Paul Tracy KV + 6.3941s 7. Graham Rahal Newman/Haas/Lanigan + 26.5700s 8. Justin Wilson Coyne + 26.9169s 9. Robert Doornbos Newman/Haas/Lanigan + 1 lap 10. Marco Andretti Andretti Green + 1 lap 11. Danica Patrick Andretti Green + 1 lap 12. EJ Viso HVM + 1 lap 13. Alex Tagliani Conquest + 1 lap 14. Hideki Mutoh Andretti Green + 1 lap 15. Dan Wheldon Panther + 1 lap 16. Ed Carpenter Vision + 2 laps 17. Ryan Hunter-Reay Foyt + 8 laps 18. Raphael Matos Luczo Dragon + 10 laps 19. Tomas Scheckter Dreyer & Reinbold + 22 laps 20. Mike Conway Dreyer & Reinbold + 32 laps Retirements/not classified: Tony Kanaan Andretti Green 34 laps Richard Antinucci 3G 20 laps Mario Moraes KV 0 laps