That meant the race went into its final stage with the order pretty much as it had been from the start: Power, Castroneves, Dixon, Franchitti and Briscoe, with Tracy now up to an impressive sixth place having started 15th. But just when it seemed that Penske were giving Will Power a red carpet to the chequered flag, Helio Castroneves pounced with 19 laps to go: taking advantage of their coming up on traffic, and with Power on the harder tyres and having already used his push-to-pass and needing to wait out the reset time, Helio pulled off an exemplary, safe and smooth pass to take the lead, only the third driver of the day to assume control of the race. Now Dixon was shaping up to take a shot at Power: like Helio he was on the grippier but shorter-life red wall tyres and clearly fancied his chances. But after an initially fast sprint the tyres seemed to fade and inconsiderate traffic got in the way - Dixon slipped back again, the moment seemingly past.
Just when the afternoon appeared a done deal, Simona de Silvestro - who was still running in 11th despite her earlier misfortune - suddenly slowed up and came to a halt out on the grass, seemingly out of fuel, and this caused a final full course caution to come out. There would be a three lap dash for the chequered flag at the restart, and so there was still everything to play for.
Will Power was still smarting at being overtaken by his team mate, and threw everything into an attempt to put the matter to rights. He mounted a strong charge going into turn 1, but Helio ran wide to just squeeze him out. Scott Dixon watched all this unfold before him, and he was alive to the opportunity: he lunged down the inside and slipped in between the two Penske cars in second, but not quite able to take Castroneves in the same move. He would have to settle for second, but that would do nicely.
And then a shock penalty was handed down from race control: Castroneves had moved from the designated line into the corner, and the move was deemed to be illegal blocking. He was handed a drive-thru penalty which handed Dixon the lead and the victory. To say that Helio was incandescent was to understate matters. He went storming off to find someone to berate and was intercepted by security, a huge man who dwarfed the tiny Brazilian - but that didn't stop Helio, who gripped the security guy's lapels looking on the verge of throwing a punch at the slightest provocation. To their credit the security team kept smiling, and let the Helio supernova burn itself out, but there was still steam coming out of Castroneves' ears when he gave an interview to the waiting TV crew, threatening to talk to his lawyers in a sarcastic throwback to the legal problems that threatened to derail his motor racing career for good in 2009.
After a strained pause while everyone waited to find out what was going on, Dixon accepted the victory in a slightly low key celebration. He'd had the ideal seat to see the "blocking" that Castroneves was accused of, and seemed not exactly completely convinced: all the commentators and pundits, meanwhile, were speechless at the ruling and failed to see any offence as they poured over the replays of the incident from all the available angles.
Not that it mattered. Race control had ruled, and that was that.