Points leader Ryan Hunter-Reay set the quickest time in qualifying for this weekend's IndyCar race at Edmonton, but the Andretti driver's 10-place grid penalty for an unapproved engine change means that Dario Franchitti will start from pole position on Sunday.
Despite a rain shower during the second qualifying segment, the track had dried sufficiently for all of the drivers who had made it to Q3 to head out on slicks, and the order changed constantly as conditions continued to improve.
Hunter-Reay was the last of the drivers in the Fast Six to post a lap, and moved to the top of the screens in the final minute with a 1m17.2338s effort that left him a scant 0.01 seconds clear of Franchitti.
"It's unfortunate to be taking the grid penalty after our first pole for the year, and my first pole for a long time," said Hunter-Reay. "But 11th is better than starting 15th or 16th.
"It was a strange session, going from full dry, to full wet, to a drying track on rain tyres, and back to reds again. You had to really keep on your toes."
Penske's Ryan Briscoe will join Franchitti on the front row, with Takuma Sato, Alex Tagliani and Helio Castroneves completing the top five.
The rain during Q2 made for a frantic scramble late in the session when the track was at its best. Those who lost out in the rush included Scott Dixon, who bumped Simon Pagenaud from sixth only to be knocked out himself by Ganassi team-mate Franchitti a moment later, and Will Power, who was bumped by Penske cohort Ryan Briscoe.
"Just a bad day after bad day after bad day," said Power. "Got to have a good result [on Sunday]."
Meanwhile, Dixon and HVM's Simona de Silvestro face 10-place grid penalties after both fitted their sixth engines for the season. Dixon's engine change came after he suffered an in-race failure in Toronto, while de Silvestro's penalty is a carry-over from the Toronto weekend. Series regulations restrict drivers to five engines over the course of the year.
Pos Driver Team/Car Time Gap
1. Ryan Hunter-Reay Andretti Dallara-Chevy 1m17.2338s
2. Dario Franchitti Ganassi Dallara-Honda 1m17.2446s + 0.0108s
3. Ryan Briscoe Penske Dallara-Chevy 1m17.4238s + 0.1900s
4. Takuma Sato Rahal Dallara-Honda 1m17.5526s + 0.3188s
5. Alex Tagliani Herta Dallara-Honda 1m17.6139s + 0.3801s
6. Helio Castroneves Penske Dallara-Chevy 1m17.6401s + 0.4063s
7. Will Power Penske Dallara-Chevy 1m27.5666s Round 2
8. Scott Dixon Ganassi Dallara-Honda 1m27.7001s Round 2
9. Simon Pagenaud Schmidt Dallara-Honda 1m27.8410s Round 2
10. Rubens Barrichello KV Dallara-Chevy 1m28.2521s Round 2
11. Graham Rahal Ganassi Dallara-Honda 1m28.6737s Round 2
12. James Hinchcliffe Andretti Dallara-Chevy 1m28.7409s Round 2
13. Justin Wilson Coyne Dallara-Honda 1m16.6190s Group 1
14. Sebastien Bourdais Dragon Dallara-Chevy 1m16.9747s Group 2
15. Josef Newgarden Fisher Dallara-Honda 1m16.7533s Group 1
16. James Jakes Coyne Dallara-Honda 1m16.9900s Group 2
17. Marco Andretti Andretti Dallara-Chevy 1m16.9881s Group 1
18. EJ Viso KV Dallara-Chevy 1m16.9920s Group 2
19. Charlie Kimball Ganassi Dallara-Honda 1m17.0078s Group 1
20. Oriol Servia Panther/DRR Dallara-Chevy 1m17.3906s Group 2
21. JR Hildebrand Panther Dallara-Chevy 1m17.5285s Group 1
22. Tony Kanaan KV Dallara-Chevy 1m17.5441s Group 2
23. Simona de Silvestro HVM Dallara-Lotus 1m17.9789s Group 1
24. Ed Carpenter Carpenter Dallara-Chevy 1m17.6918s Group 2
25. Mike Conway Foyt Dallara-Honda 1m18.8781s Group 2