DETROIT – Graham Rahal is relishing a remarkable run — this weekend in the Motor City and over the past two-plus seasons.

Rahal completed a doubleheader sweep at the Detroit Grand Prix on Sunday and became IndyCar's first two-time winner this season.

Driving for father and former racing star Bobby Rahal's Rahal Letterman Lanigan Racing team, Rahal has six career victories, five in two-plus seasons during a stretch of success that followed a six-year winless streak.

"Through the ups and downs of my career, when you get a chance to win a race, you never take it for granted," he said. "So, it's pretty special for me."

It looked like a given Rahal's Honda-powered car was going to finish first easily, for the second straight race, until there was a single-file final restart with two laps to go in the 70-lap race. A red flag stopped the race for 18 minutes after 67 laps because Spencer Pigot's car had a mechanical failure. The Ed Carpenter Racing driver got out of his smoke-filled car after a yellow flag came out because James Hinchcliffe's car stalled.

That wasn't enough to let the competition close in on Rahal, who pulled away for victory on the Belle Isle course. He finished 1.17 seconds ahead of Josef Newgarden's Chevrolet, a day after getting to the checkered flag six-plus seconds ahead of the competition.

"I couldn't pull anything too risky because I didn't have any grip on the tires," Newgarden said.

Will Power of Team Penske was third Sunday, giving Chevy a better showing than on Saturday when Honda swept the podium near General Motors' world headquarters.

"We didn't get the win, but it was a good showing," Power said. "Honda has definitely found something, but it's not reliable."

Rahal became the first to sweep in Detroit since it began hosting doubleheaders in 2013. He became the first to win two IndyCar races in a weekend since Scott Dixon pulled off the feat four years ago in Toronto. His team won consecutive races for the first time since Kenny Brack drove pulled off the feat in Japan and at Milwaukee in 2001. Rahal, who is from New Albany, Ohio, became the first American to win in Detroit on Saturday since Michael Andretti in 1996.

Indianapolis 500 winner Takuma Sato earned the pole earlier in the day and finished fourth with his Honda-powered car for Andretti Autosport.