Polesitter Newgarden made a great jump at the start, emphasized by Penske-Chevrolet teammate Power dropping down to the back of the field with engine issues and needing to pit at the end of a very slow first lap.

Ryan Hunter-Reay’s Andretti Autosport-Honda jumped up into second, while teammate Rossi had to muscle Robert Wickens’ Schmidt Peterson-Honda wide at Turn 5 on the opening lap in order to retain his third place.

The incident dropped the Canadian down to sixth, behind the fast-starting Rahal Letterman Lanigan Racing-Honda of Takuma Sato and Sebastien Bourdais’ Dale Coyne Racing with Vasser-Sullivan entry.

Defending race winner Scott Dixon ran seventh ahead of Graham Rahal and Marco Andretti (up from 15th) , and Ed Carpenter Racing’s Spencer Pigot passed Simon Pagenaud – running primary tires on his Penske – on the run to Canada corner. Tony Kanaan of AJ Foyt Racing was another driver who made excellent progress, vaulting from 18th to 12th in the opening two laps.

Pigot moved past Andretti into ninth on Lap 6, while Kanaan and Charlie Kimball of Carlin – both running a four-stop strategy – pitted for fresh alternate tires.

Newgarden finally pushed his lead on Hunter-Reay to over a second on Lap 8. A lap later, Bourdais ducked into the pits from fifth place to make a long stop with a gear control unit failure, which was repaired but not until he dropped to 22nd.

By lap 10, Newgarden, Hunter-Reay, Rossi and Sato were running around 0.9sec apart in the top four position, with Wickens four seconds off this train, having resisted an early challenge by Dixon, with Bourdais’ troubles boosting Rahal, Pigot, Andretti and Pagenaud.

Sato, Rahal and Pigot were first of the top 10 runners to stop, at the end of Lap 13. The following lap Newgarden, Hunter-Reay, Rossi and Wickens all stopped for primary tires, leaving Dixon out front for one lap.

That extra lap didn’t help Dixon as he resumed in sixth behind Wickens, with early-stopping Kanaan briefly in seventh ahead of Rahal, Pigot, Andretti and Pagenaud before Kanaan stopped again.

The top four continued to run in line astern, saving fuel, while Wickens worked hard to close the gap ahead and join the tail of that group, and Dixon too, would make it a clear top six.

Around 17sec off the lead, Pagenaud moved past Andretti and into ninth on Lap 23.

Rossi had fallen 3.5sec behind the Newgarden vs Hunter-Reay battle by the second round of pitstops, which began with Sato, Rahal, Pagenaud, Pigot stopping on Lap 27, Rossi and Wickens on 28, and Newgarden, Hunter-Reay and Dixon on 29.

Rossi and Wickens had pulled out of the pits in front of the warm-tied Sato, but the Japanese driver dived down the inside of Wickens into Turn 3. The RLLR driver then also tried to squeeze around the outside of Rossi at Turn 5, but lost momentum on the rumble strip, and the pair stayed level up to Turn 6, where Rossi ran Sato out of road. Sato’s trip across the grass allowed Wickens in front.

This trio were now all behind Dixon, who had a very strong second stop, but Rossi closed in on the Ganassi car by Lap 30. Just a couple of seconds ahead, Hunter-Reay – on primaries – was putting pressure on Newgarden on the alternate compound.

On Lap 35, Wickens was bumped back to seventh as Rahal made it two RLLR cars in the top six, and closed on teammate Sato who had to lean on his push to pass to keep the #15 behind him.

Suddenly it became a battle for fourth, as at the start of Lap 38, Rossi slowed with a left-front puncture and lost a camber shim. Both the RLLR cars and Wickens passed him before the NAPA Andretti car pulled in the following lap and the car was shut down temporarily for repairs. The 2016 Indy 500 winner would resume the race in 19th.

Sato, Rahal, Wickens, Pagenaud and Pigot all stopped at the end of Lap 41, and Pagenaud was delayed as Wickens was released from his stop into Pagenaud’s path. It was enough to drop Pagenaud behind Pigot – and ultimately he lost ninth to Ganassi's Ed Jones, too – while Wickens gained, splitting the RLLR cars to run fifth, ahead of Rahal.

Dixon hit pitlane on Lap 42 to pick up a set of fresh red alternate compound tires, while Newgarden was able to stretch his lead over Hunter-Reay to 2.2sec before they both stopped at the end of Lap 43.

As the two leaders emerged from pitlane, Dixon bore down on them and had the luxury of much warmer tires, but a major moment for the Ganassi driver in Turn 14 gave Hunter-Reay the reprieve he needed as he tried to chase down Newgarden.

Hunter-Reay soon chopped Newgarden's lead to half a second, before the reigning champion started pulling away once more, and Dixon closed on the second-placed Andretti car.

Further back, Pagenaud tried to pass Jones’ Ganassi car, and as the #22 Penske car made his maneuver, the pair banged wheels, an incident that went under stewards’ review. No action was taken.

Newgarden reeled off the 10th win of his career, winning by 3.4sec over Hunter-Reay who beat Dixon by 2.1sec. Sato was 9sec down on Dixon but a similar distance ahead of Wickens, who in turn was about 9sec in front of Rahal.

Pagenaud grabbed seventh from Pigot on the last lap, but the ECR driver could be satisfied with his best finish of the year while Jones and James Hinchcliffe (SPM) completed the top 10.

Bourdais recovered to grab 13th, while Rossi was eventually classified 16th.

The results leave Dixon in the lead with 393 points, followed by Hunter-Reay (348), Rossi (348), Newgarden (343), Power (328), Graham Rahal (278), Robert Wickens (274), Simon Pagenaud (255), Sebastien Bourdais (235) and Marco Andretti (232).

Race results:

Pos.	#	Driver	Laps	Team	Time/Gap	Mph	Pits
1	1	Josef Newgarden	55	Team Penske	1:40'16.4165	132.101	3
2	28	Ryan Hunter-Reay	55	Andretti Autosport	3.3759	132.026	3
3	9	Scott Dixon	55	Chip Ganassi Racing	5.4902	131.980	3
4	30	Takuma Sato	55	Rahal Letterman Lanigan Racing	14.8772	131.775	3
5	6	Robert Wickens	55	Schmidt Peterson Motorsports	23.8993	131.578	3
6	15	Graham Rahal	55	Rahal Letterman Lanigan Racing	32.5513	131.390	3
7	22	Simon Pagenaud	55	Team Penske	42.1868	131.181	3
8	21	Spencer Pigot	55	Ed Carpenter Racing	42.5336	131.173	3
9	10	Ed Jones	55	Chip Ganassi Racing	46.2118	131.094	3
10	5	James Hinchcliffe	55	Schmidt Peterson Motorsports	47.5359	131.065	3
11	98	Marco Andretti	55	Andretti Herta Autosport	48.1468	131.052	3
12	20	Jordan King	55	Ed Carpenter Racing	53.4242	130.938	3
13	18	Sébastien Bourdais	55	Dale Coyne Racing	1'00.3249	130.789	3
14	14	Tony Kanaan	55	A. J. Foyt Enterprises	1'05.2583	130.683	4
15	4	Matheus Leist	55	A. J. Foyt Enterprises	1'09.7681	130.586	3
16	27	Alexander Rossi	55	Andretti Autosport	1'23.4715	130.293	3
17	59	Max Chilton	55	Carlin	1'24.3709	130.274	3
18	23	Charlie Kimball	55	Carlin	1'43.1557	129.874	4
19	88	Gabby Chaves	54	Harding Racing	1 lap	129.084	5
20	32	Alfonso Celis Jr.	54	Juncos Racing	1 lap	128.585	3
21	19	Zachary Claman De Melo	54	Dale Coyne Racing	1 lap	128.305	4
22	26	Zach Veach	54	Andretti Autosport	1 lap	127.827	5
23	12	Will Power	2	Team Penske	53 laps	15.486	2