Dario Franchitti became IndyCar champion for the third time in four years by taking eighth place in the Homestead finale, as season-long points leader Will Power lost the title after brushing the wall and damaging his suspension.
In a spectacular night for Ganassi, Franchitti's team-mate Scott Dixon took the race victory - the Scot having led most of the race until Power's retirement allowed him to play it cool in the closing laps.
It looked like Penske driver Power was facing an uphill battle from the outset, as the Ganassi duo settled into first and second - Dixon running dutifully behind polesitter Franchitti and protecting him against attacks from rivals.
They could not dominate for long, though. By lap 33, Andretti Autosport's Tony Kanaan had worked his way into contention and managed to split the Ganassi duo, and in the first pitstops Penske vaulted Ryan Briscoe from fourth to second, allowing the Australian to put Franchitti under plenty of pressure.
After several laps of side by side racing, Briscoe got into the lead on lap 59, with Franchitti losing momentum in the process and falling to fourth.
He had the speed to swiftly fight back though, regaining the lead just 14 laps later, while Briscoe's tenure up front had only been brief before Kanaan passed him.
Meanwhile Power had fallen as low as ninth in the first stint but picked up pace in the second half, coming back through to fourth behind Franchitti, Kanaan and Dixon, and ahead of the other two Penske drivers.
But that was not going to be enough for the championship, especially once Franchitti had clinched the two bonus points for leading the most laps. And then came the terminal blow to Power's title hopes, when he understeered into the Turn 4 wall on lap 134.
It was a series of glancing blows rather than a violent impact, but the right rear suspension was damaged. Six laps were lost while repairs were effected, and Power was soon back in again, not convinced that all the damage had been resolved. He eventually climbed from the car, and could only watch from the sidelines and hope Franchitti hit trouble.
With his rival sidelined, Franchitti was playing it safe, relinquishing the lead to Dixon on the next restart and pitting under the next yellow to top up with fuel and avoid any danger of running dry late-on.
Marco Andretti (Andretti Autosport) fought through to have a brief spell in the lead, but lost his chance of victory by pitting for a fuel top-up under a debris caution with 35 laps to go - only for Milka Duno to crash heavily 10 laps later and cause another yellow that resolved everyone else's fuel mileage worries.
The brief spell between those cautions had seen a stunning three-way battle for the lead between Dixon, Helio Castroneves and Kanaan, but after the last restart Dixon broke clear, disappearing up the road to claim victory while Kanaan suddenly had his hands full fending off team-mate Danica Patrick.
As Dixon went on to win by 2.7 seconds, Patrick finally muscled her way past Kanaan with a lap to go, holding on to clinch the runner-up spot by 0.0111s.
Briscoe lost his chance of victory by pitting just before the yellow for Power's incident, but recovered to fourth ahead of team-mate Castroneves.
Vitor Meira scored an outstanding sixth for AJ Foyt's team, followed by Andretti, Franchitti, and Panther's Dan Wheldon. Alex Lloyd clinched the rookie of the year title by finishing 12th for Dale Coyne Racing.
Graham Rahal (Newman/Haas) and Ryan Hunter-Reay (Andretti) recovered from disappointing qualifying results to claim 10th and 11th, while Ed Carpenter (Panther/Vision), Takuma Sato (KV) and Justin Wilson (Dreyer & Reinbold) went in the opposite direction - falling back to 13th, 18th and 21st in the race after showing well on Friday.
Sato's team-mate EJ Viso was a top six contender initially, until he pulled away from a pitstop with the fuel hose still attached. Viso's car was briefly engulfed in flames, eventually shed the fuel nozzle on the track, and then had to take a penalty, leaving him two laps down. Kanaan had a very similar, but less dramatic, incident later on and lost less time.
Almost unnoticed amid the championship battle, Sebastian Saavedra had an impressive first outing with Conquest, finishing 16th having run as high as 10th.
Pos Driver Team Time/Gap 1. Scott Dixon Ganassi 1h52m08.5580s 2. Danica Patrick Andretti + 2.7587s 3. Tony Kanaan Andretti + 2.7698s 4. Ryan Briscoe Penske + 3.7827s 5. Helio Castroneves Penske + 5.3324s 6. Vitor Meira Foyt + 7.2126s 7. Marco Andretti Andretti + 8.3637s 8. Dario Franchitti Ganassi + 11.1401s 9. Dan Wheldon Panther + 22.2521s 10. Graham Rahal Newman/Haas + 1 lap 11. Ryan Hunter-Reay Andretti + 1 lap 12. Alex Lloyd Dale Coyne + 1 lap 13. Ed Carpenter Panther/Vision + 1 lap 14. Alex Tagliani FAZZT + 1 lap 15. Bertrand Baguette Conquest + 1 lap 16. Sebastian Saavedra Conquest + 1 lap 17. Raphael Matos De Ferran Dragon + 1 lap 18. Takuma Sato KV + 1 lap 19. EJ Viso KV + 2 laps 20. Hideki Mutoh Newman/Haas + 2 laps 21. Justin Wilson Dreyer & Reinbold + 2 laps 22. Sarah Fisher Sarah Fisher + 3 laps 23. Simona de Silvestro HVM + 3 laps Retirements: Milka Duno Dale Coyne 170 laps Will Power Penske 143 laps Ana Beatriz Dreyer & Reinbold 42 laps Mario Moraes KV 25 laps