The Team Penske driver used a two-stop strategy to hold off a charging Rossi (Andretti Autosport), who was on a three-stop strategy, and take the chequered flag by just over a second.
Having moved into the Top 10 by Lap 5, ahead of fellow primary-tyre runner Scott Dixon, Power continued his charge, passing Arrow McLaren SP’s Pato O’Ward for fourth on Lap 10 before getting past Meyer Shank Racing team-mates Helio Castroneves and Simon Pagenaud for second on successive laps.
Power took the lead on Lap 14, with Dixon in second, before Rossi, thanks to his early first stop had charged through to sixth and went past Josef Newgarden to claim fifth on Lap 16.
Power had pulled a five second lead on Dixon before pitting on Lap 25, and he emerged with another set of primaries, whereas Dixon and Alex Palou, running in fourth, went one more lap and both grabbed a set of the fragile alternates.
Power’s lead over Dixon was out to 8.5 seconds on Lap 35, as he was continually able to turn in 1min16.9sec laps.
Rossi hadn’t closed the gap on Power once past Dixon and so once he got embroiled in traffic, he pitted for the third and final time, and his pitcrew out comfortably ahead of Dixon.
Alexander Rossi, Andretti Autosport Honda
Photo by: Jake Galstad / Motorsport Images
Power’s lead over Rossi on Lap 50 was 44s when he stopped for his reds, closing to 16s after his outlap. By Lap 58, he was still 11.7s to the good, and managed to squeeze 12 more laps out of his reds to win by 1.0027sec.
Dixon was six seconds further behind Rossi, ahead of Newgarden, O’Ward and Palou.
A very strange start where only the top eight or nine cars were in formation saw Team Penske-Chevrolet’s Newgarden easily convert his pole into the lead, while Pagenaud and Castroneves passed Sato to claim second and third.
Behind ran O’Ward and Colton Herta, while Rossi immediately started slicing through the field, and by Lap 3 he was into sixth.
He then pitted the following lap to get off the alternate tyres and tackle the race on a three-stop strategy.
Power and Dixon outbraked Marcus Ericsson on Lap 7 to claim seventh and eighth respectively. The alternate-tyred cars were now struggling, and the pair passed Herta to claim sixth and seventh which became fourth and fifth and sixth when Sato pitted.
Scott Dixon, Chip Ganassi Racing Honda
Photo by: Michael L. Levitt / Motorsport Images
Power, Dixon and Palou passed Newgarden to assume the top three spots on Lap 14, and on Lap 16 Kirkwood passed Newgarden, too. Rossi, thanks to his early first stop had charged through to sixth and he went past Newgarden to claim fifth on Lap 16.
Pagenaud managed to make it to Lap 17 on his reds, pulling out of seventh place to grab a set of blacks, and Newgarden and O’Ward stopped a lap later.
On Lap 37, Rossi was within striking distance of Palou and dived down the inside of him at Turn 3 on Lap 39. Dixon proved a tougher nut to crack, finally getting it done on Lap 43, again at Turn 3.
Palou pitted on Lap 43, which allowed Kirkwood, Newgarden, O’Ward and Ericsson ahead. But the following lap, Dixon, Newgarden and O’Ward were in and they emerged still ahead of Palou.
Kirkwood pitted on Lap 48 and emerged in ninth, but he tagged the wall on his out lap and bent his suspension.
Rinus VeeKay crashed out of seventh place on the last lap, promoting Ericsson and Herta into seventh and eighth.