Andretti Autosport's Tony Kanaan took his first IndyCar victory since June 2008 as he overcame Penske's Helio Castroneves in a closely fought race at Iowa Speedway.
Long-time leader Dario Franchitti was denied by late-race gearbox problems, while Scott Dixon and Will Power both faded after fighting for the lead. As they did, EJ Viso charged through to a career-best third, making up for KV Racing's disappointment when his teammate Takuma Sato crashed out of the same spot.
Polesitter Power had led the early running for Penske under pressure from the battling Marco Andretti (Andretti Autopsport) and Dixon (Ganassi), while Franchitti got off to a quiet start and fell as low as sixth.
Power's tenure up front abruptly ended on lap 33 when his Penske Dallara's handling went awry and when he braked sharply to avoid a slow-moving Hideki Mutoh, he started tumbling down the order. It was Andretti who took up the lead, but 10 laps later he ran into similar handling issues and went into an even more dramatic free fall.
By then, the Ganassi duo were in position to benefit, Franchitti having climbed to second ahead of Dixon. There was no hint of team orders as they went head to head up front, with the two red cars repeatedly swapping places over the next two stints.
Along the way, Dixon survived a pit-lane traffic jam that resulted in firm contact between him and Castroneves, who in turn was being pinched on the outside by Kanaan's pit exit trajectory. The No. 3 Penske briefly went airborne and landed with slightly skewed steering, yet remarkably all three cars escaped significant damage.
As the Ganassi drivers diced after a mid-race restart following a crash for Sarah Fisher, Andretti Autosport duo Kanaan and Ryan Hunter-Reay joined in and got between them, with Kanaan – up from 15th on the grid – then embarking on a long dice with Franchitti that saw them take turns at the front.
Behind them, Takuma Sato – who had been on the fringe of the top six all afternoon – suddenly picked up pace and passed Hunter-Reay and Dixon in quick succession to take third. But he had only just gotten there when he understeered into the wall while lapping Alex Lloyd's Dale Coyne car.
Everyone made their final pit stops under the next yellow, and Kanaan lost ground when Hunter-Reay clipped his left front, fortunately without harm to the tire changer. While Kanaan fell to third, quick Penske pit work got Castroneves up to second behind Franchitti – which became the lead when the Ganassi Dallara's gearbox malfunctioned 43 laps from the end.
That set up a final shootout between Castroneves and Kanaan. When Castroneves held on through a close call as they lapped Kanaan's teammate Andretti, it looked like he had secured enough breathing space to claim the win. But with 10 laps to go Kanaan mounted a final surge and slipped through on the inside and then charged away to finally end his victory drought.
Castroneves held onto second ahead of Viso, who crept into contention as the race progressed. In the closing stages, Ryan Briscoe – who'd been suffering oversteer issues for much of the race – nipped past teammate Power, and the pair of them then swamped a fading Dixon to claim fourth and fifth. Dixon has nonetheless now passed teammate Franchitti in the championship standings, but both are once more behind Power heading into five road/street course races.
The last unlapped car was Vitor Meira, who produced an excellent performance to give A.J. Foyt's team seventh place. Hunter-Reay's pit incident – and subsequent drive through penalty – dropped him to eighth, while Graham Rahal's debut for Dreyer & Reinbold saw him briefly lead when out of sequence on strategy and eventually finish ninth ahead of Danica Patrick.
Rahal's D&R teammate Justin Wilson's race ended on the first lap when he spun and collected Mario Moraes' KV Racing car.
Pos Driver Team Time/Gap
1. Tony Kanaan Andretti 1h42m12.4036s
2. Helio Castroneves Penske + 4.2030s
3. EJ Viso KV + 5.2538s
4. Ryan Briscoe Penske + 9.0536s
5. Will Power Penske + 9.5902s
6. Scott Dixon Ganassi + 15.2683s
7. Vitor Meira Foyt + 16.8703s
8. Ryan Hunter-Reay Andretti + 1 lap
9. Graham Rahal Dreyer & Reinbold + 1 lap
10. Danica Patrick Andretti + 1 lap
11. Dan Wheldon Panther + 1 lap
12. Alex Tagliani Fazzt + 2 laps
13. Alex Lloyd Dale Coyne + 2 laps
14. Raphael Matos De Ferran Dragon + 3 laps
15. Marco Andretti Andretti + 6 laps
16. Mario Romancini Conquest + 6 laps
17. Bertrand Baguette Conquest + 13 laps
Dario Franchitti Ganassi 212 laps
Takuma Sato KV 177 laps
Hideki Mutoh Newman/Haas 131 laps
Simona de Silvestro HVM 128 laps
Sarah Fisher Sarah Fisher 92 laps
Milka Duno Dale Coyne 31 laps
Justin Wilson Dreyer & Reinbold 0 laps
Mario Moraes KV 0 laps