Will Power triumphed in a thrilling first race in this weekend's IndyCar double-header in Detroit.
A combination of a scrambled grid and a succession of yellows made for almost as many strategies as there were drivers during the first half, but towards the end it boiled down to a straight fight between Power and Graham Rahal.
Power had the track position, but Rahal had a car that had been working well all afternoon and it took a fairly robust block from the Australian to retain the lead at the final restart.
With half a dozen laps remaining Power's lead had been stripped from one second to around 0.6s, and Rahal was clamped squarely to his rear over the final two laps.
But he was never able to find a way around, and Power went on to cross the line just 0.3s ahead, delivering hometown wins to both team owner (and race promoter) Roger Penske and engine supplier Chevrolet.
"Graham made it very difficult," said Power, who had struggled badly in qualifying and started from 16th.
"He never gave up. Every time I tried to relax he was straight back at me."
Power's road to victory included the addition of another chapter to his growing rivalry with Simon Pagenaud.
The pair touched on lap five when a wheel-to-wheel scrap culminated in Pagenaud making what he later admitted was "probably an optimistic move" to Power's inside and being pancaked into the wall. The consequent suspension damage ended his afternoon.
Meanwhile, Rahal was disappointed to fall just short of the win while being simultaneously pleased to finally get a good result on the board after a poor start to the year for family team Rahal Letterman Lanigan.
"I feel like we got a monkey off our back today," he said. "I knew I only had one real opportunity and that was on the restart and [Will] blocked me - which was fair enough; I would have done the same thing."
Ganassi's Tony Kanaan was on the same strategy at the end and completed the podium, although he had no answer to the pace of Power and Rahal and spent the final laps making sure that he kept ahead of Justin Wilson.
Polesitter Helio Castroneves rounded out the top five; the Brazilian fast whenever he was in front, but ultimately being thwarted by the timing of the yellows.
Accidents and other mishaps derailed several other potential contenders. Jack Hawksworth was looking very strong during the opening stint, running comfortably in second before his brake rotor exploded right before his first stop. He eventually rejoined four laps down, only to become involved in a last-lap incident with Mikhail Aleshin.
Indeed, the Russian's afternoon had been almost as eventful. He became the first driver from his country to lead an IndyCar race when he took a stint at the front during the stops, only to be penalised for blocking Takuma Sato, who was four laps down. Earlier, he had survived a brief clash with James Hinchcliffe.
Mike Conway was running in the top four for Ed Carpenter Racing when he made a mistake and clouted the wall, and later, Josef Newgarden did the same thing to cost himself a chance at a top 10 finish.
It was a miserable afternoon for Indianapolis 500 winner and championship leader Ryan Hunter-Reay, who started from the last row after an accident in qualifying, made little impression during the race, and then lost the rear of his car and crashed into the wall on the final lap.
Results - 70 laps: Pos Driver Team/Engine Time/Gap 1. Will Power Penske/Chevy 1h49m29.9323s 2. Graham Rahal Rahal/Honda +0.3308s 3. Tony Kanaan Ganassi/Chevy +5.5096s 4. Justin Wilson Coyne/Honda +8.5951s 5. Helio Castroneves Penske/Chevy +10.7365s 6. James Hinchcliffe Andretti/Honda +11.5074s 7. Carlos Munoz Andretti/Honda +14.8813s 8. Carlos Huertas Coyne/Honda +26.5965s 9. Charlie Kimball Ganassi/Chevy +32.5852s 10. Marco Andretti Andretti/Honda +33.1818s 11. Scott Dixon Ganassi/Chevy +33.3522s 12. Juan Pablo Montoya Penske/Chevy +34.0094s 13. Sebastien Bourdais KV/Chevy +36.0240s 14. Sebastian Saavedra KV/Chevy +37.0532s 15. Ryan Briscoe Ganassi/Chevy +56.6632s 16. Ryan Hunter-Reay Andretti/Honda -1 lap* 17. Mikhail Aleshin Schmidt/Honda -2 laps* 18. Takuma Sato Foyt/Honda -4 laps 19. Jack Hawksworth Herta/Honda -5 laps* * Not running at finish Retirements: Josef Newgarden Fisher/Honda 36 laps Mike Conway Carpenter/Chevy 14 laps Simon Pagenaud Schmidt/Honda 4 laps