Juan Pablo Montoya led Helio Castroneves to a Team Penske one-two to secure his first win since his IndyCar comeback with a superb drive at Pocono on Sunday.
The Colombian started from pole and ran amongst the lead pack all afternoon, finally moving into the lead for the final time when an off-strategy Tony Kanaan was forced to pit for fuel with four laps remaining.
For most of the day Montoya's main threat had been the other Penske car of Will Power, who had jumped ahead of him at the start.
The pair remained in close quarters, with the key moment coming when Montoya attacked the Australian on the only restart.
The pair ran side-by-side for a lap before Montoya slotted back into second, but moments later he attacked again.
This time, he glanced Power's left-rear and tore off a section of his own front wing, but the damage had little impact upon his speed. More importantly for Montoya, he made the move stick.
"I want to thank Roger [Penske] for believing in me," Montoya said.
"After so many years out of open-wheelers he believed I could do it, and here we are. It was awesome.
"[After the contact] I had a little bit of understeer. You either do it [make a move] or you don't. I had to do it. That was the win move, and I had to do it."
Power should have been on the podium as well, but once again he was the architect of his own undoing when he was penalised for blocking Castroneves with just 25 laps remaining.
He recovered to 10th, but in a race paying double-points it was a potentially catastrophic error, and he now heads to next weekend's race at Iowa sharing the championship lead with Castroneves.
"I let [Castroneves] go," said Power. "I actually touched the brakes. I don't know what to say.
"Another penalty, another drive-though and another opportunity lost."
Ganassi driver Kanaan was a clear match for the Penskes on pace during the first two-thirds of the race: indeed, he spent roughly three stints in the lead.
His fortunes changed when Graham Rahal stopped with a mechanical problem and brought out the yellows with 39 laps to run, and Ganassi decided to pit the Brazilian in the hope that there would be enough time under caution to negate the need for any more stops.
Kanaan stopped again, still under yellows, for a top-up three laps later, but with fuel stints running to around 31 laps, he wasn't going to make it to the end without help from elsewhere.
As it transpired, that help never came, and a chance to jump-start an otherwise disappointing season was lost.
The bright spot for Ganassi was that both Ryan Briscoe and Scott Dixon managed to make up a lot of ground after relatively lowly starting spots; the pair finishing sixth and seventh respectively.
It was also an afternoon of mixed fortunes for Andretti Autosport, which had rookie Carlos Munoz complete the podium in third, and all three of its other drivers strike problems.
Ryan Hunter-Reay's afternoon was ruined early by a suspension problem that cost him 19 laps, while drive-through penalties for pitlane speeding were issued to both Marco Andretti and James Hinchcliffe.
Results - 200 laps:
Pos Driver Team/Engine Time/Gap
1. Juan Pablo Montoya Penske/Chevy 2h28m13.1798s
2. Helio Castroneves Penske/Chevy +2.3403s
3. Carlos Munoz Andretti/Honda +2.9653s
4. Ryan Briscoe Ganassi/Chevy +3.8431s
5. Scott Dixon Ganassi/Chevy +4.6933s
6. Simon Pagenaud Schmidt/Honda +6.0105s
7. Mikhail Aleshin Schmidt/Honda +8.3658s
8. Josef Newgarden Fisher/Honda +8.9506s
9. Marco Andretti Andretti/Honda +9.4477s
10. Will Power Penske/Chevy +17.2301s
11. Tony Kanaan Ganassi/Chevy +22.0701s
12. James Hinchcliffe Andretti/Honda -1 lap
13. Ed Carpenter Carpenter/Chevy -1 lap
14. Justin Wilson Coyne/Honda -1 lap
15. Sebastian Saavedra KV/Chevy -1 lap
16. Sebastien Bourdais KV/Chevy -1 lap
17. Charlie Kimball Ganassi/Chevy -2 laps
18. Ryan Hunter-Reay Andretti/Honda -19 laps
Graham Rahal Rahal/Honda 157 laps
Carlos Huertas Coyne/Honda 89 laps
Takuma Sato Foyt/Honda 25 laps
All drivers use Dallara chassis