Graham Rahal has become the first repeat IndyCar race winner of 2017 and the first to sweep the Detroit Grand Prix double-header.

Rahal faced a sterner challenge in Race 2, but survived a late-race restart to beat Josef Newgarden and Will Power to the chequered flag.

Takuma Sato qualified on pole, breaking the track record which Rahal set just a day earlier, and got a good start to lead the field through a clean opening lap.

The #26 Andretti Autosport Honda driver was out to a 1.8s lead when Rahal (#15 Rahal Letterman Lanigan Honda) rounded up Ryan Hunter-Reay for third position on Lap 9, making contact in the process.

While Rahal was unperturbed, Hunter-Reay seemed to be suffering and Helio Castroneves made a move on the #28 Andretti Autosport Honda a lap later.

Ironically, contact between those two not only damaged Hunter-Reay’s front wing but also cut Castroneves’ left-rear tyre, and the #3 Team Penske Chevrolet had to be brought into the pits.

Penske drivers Will Power and Simon Pagenaud, and Andretti team-mate Alexander Rossi, relegated Hunter-Reay to sixth over the next handful of laps before the 2012 champion finally pitted and assumed a three-stop strategy.

Rahal and Power caught Sato towards the end of their first stints as most of the front-runners looked to set up for a two-stop strategy.

Sato and Power pitted on Lap 23 of 70, while Rahal waited another lap and re-joined in the effective race lead.

Meanwhile, Newgarden had risen to first position as he locked himself into a three-stop strategy.

The #2 Team Penske Chevrolet driver used his clear air to lap up to two seconds per lap quicker than the chasing pack before taking his second pit stop on Lap 29, leaving Rahal the new leader by 14s over Sato.

Those two and third-placed Power completed their final pit stops on Lap 47, the Australian passing the Japanese in pit lane, leaving Newgarden out front again.

Newgarden pitted for a third time on Lap 49 and resumed in second position, but faced a 16s deficit to Rahal.

However, with Rahal catching traffic in the form of Hunter-Reay, who had not been a factor since his early incidents, Newgarden was gaining around a second per lap on car #15.

Rahal looked to have just enough in reserve to get home, particularly when Hunter-Reay finally let him go on Lap 66, but then the first and only Caution came when Ryan Hinchcliffe’s Schmidt Peterson Honda failed to proceed.

That became a red flag when Spencer Pigot’s Ed Carpenter Chevrolet blew a turbo, but the effect was the same – Rahal would face a late restart with the lapped cars moved to the back of the field.

However, Newgarden struggled on cold tyres when the green flag did wave again with two laps remaining, and the front-runners ran unchanged to the finish.

The top 10 was Rahal, Newgarden, Power, Sato, Pagenaud, Scott Dixon (Chip Ganassi Honda), Rossi, Charlie Kimball (Chip Ganassi Honda), Castroneves, and Tony Kanaan (Chip Ganassi Honda).

Dixon, who took over the championship lead in Race 1, extends his advantage ahead of the next race at Texas Motor Speedway from June 9-10.

Results: Detroit Grand Prix Race 2

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

Note: Additional pit stop counted for most drivers due to red flag

Championship points