Josef Newgarden has taken an all-the-way victory in IndyCar at Road America as an engine problem meant Will Power’s race was all but over before it began.

Newgarden had Ryan Hunter-Reay following in close proximity for most of the 55-lap race but the latter similarly remained second for the duration, but for pit stops.

Scott Dixon made ground in each of the first two stints of what was a three-stop race for most, to advance from eighth at the start to third at the finish and extend his series lead.

Newgarden and Power locked out the front row for Team Penske but the latter dropped like a stone when the green flag waved with the issue traced back to a broken header in the #12 Chevrolet.

It gave the 2017 Verizon IndyCar Series champion clear passage to the first corner and Newgarden edged away to a lead of around 1.3s over Hunter-Reay in the first stint.

They pitted together on Lap 14, each switching from reds to a stint on black tyres, and such was the story of the race as they ran almost identical strategies with barely more than two seconds between until the last lap.

While Hunter-Reay initially closed up on Newgarden early in the second stint, he couldn’t get close enough to challenge.

They took their respective second pit stops after Lap 29 with the #1 Chevrolet taking scuffed reds and the #28 Andretti Autosport Honda another set of blacks, the only deviation in strategy.

Newgarden stretched the lead to two seconds by the time they pitted for the last time with 12 laps remaining, both taking new reds.

Despite Hunter-Reay gaining some ground as he hustled with push-to-pass to keep Dixon at bay, Newgarden had a comfortable run to the finish for his first win at Road America.

Dixon, the 2017 Road America race winner, picked up two positions in the first stint including that gained due to Power’s problem.

He initially stayed out a lap longer than most at the first pit stop cycle, before advancing three positions through the second cycle.

The #9 Chip Ganassi Honda was three seconds behind Hunter-Reay when he pitted on Lap 42 but was half a chance to execute a pass when Hunter-Reay rejoined the circuit a lap later.

The New Zealander couldn’t get close enough to try a move, in part when he broke into a slide at Turn 14, but picked up a solid points haul in third.

Alexander Rossi, one of Dixon’s key title rivals, finished all the way back in 16th after an early final pit stop for loose steering.

He sat fourth having just been cleared of wrongdoing regarding contact with Takuma Sato as the Japanese driver tried to pass on the outside through Turns 5 and 6.

However, the #27 Honda lost all pace and had to pit on Lap 38, at which time the Andretti Autosport crew tightened up the left-front corner.

Rossi confirmed post-race that the camber shims had fallen out of his car.

Sato finished a season-high fourth in the #30 Rahal Letterman Lanigan Honda, two positions ahead of team-mate Graham Rahal in Car #15.

Splitting them was Robert Wickens, who lost three positions when he was forced onto the dirt as Rossi made an aggressive move for third on Lap 1, a similar incident to that between Rossi and Sato.

He regained a position due to misfortune for Sebastien Bourdais and sat on the cusp of the top five thereafter in the #6 Schmidt Peterson Honda.

Seventh through 10th were Simon Pagenaud (#22 Team Penske Chevrolet) despite starting 14th, Spencer Pigot (#21 Ed Carpenter Racing Chevrolet), Ed Jones (#10 Chip Ganassi Honda), and James Hinchcliffe (#5 Schmidt Peterson Honda).

Bourdais took 13th after an early pit stop for a gear control unit problem took the #18 DCR w/ Vasser-Sullivan Honda out of the top five.

Race 11 is the Iowa Corn 300 in a fortnight’s time (July 7-8 local time).

Race results: Road America

(C)hassis: D=Dallara | (E)ngine: C=Chevy, H=Honda | (T)yre: F=Firestone

Series points