DETROIT -- Graham Rahal completed a double dose of fun Sunday in the IndyCar Series, although the excitement was momentarily tempered by a red flag.
The son of 1986 Indianapolis 500 winner Bobby Rahal dominated a 70-lap race in the Detroit Grand Prix for the second consecutive day, but he had to fight through a two-lap shootout to become the first IndyCar driver to win both races at Belle Isle Park since the doubleheader format was instituted five years ago.
Josef Newgarden finished second and Will Power was third. Indianapolis 500 winner Takuma Sato took fourth and Simon Pagenaud came in fifth.
Rahal led 55 laps in Saturday's race and another 41 laps on Sunday. He won the first one by 6.14 seconds and the second by 1.1772 seconds.
Rahal had a seven-second lead when a late caution waved Sunday, and he had to sit through a 20-minute red flag as officials cleaned oil off the track from two unrelated engine failures.
Such dominance hasn't been seen in this series in some time. Rahal became the first driver to win two races this season, and of the five doubleheader events (10 races) on the temporary street circuit, he is only the third driver to win for a second time. The others are Sebastien Bourdais and Power.
The last driver to sweep an IndyCar doubleheader weekend was Scott Dixon in 2013 in Toronto.
Rahal is in good company all around. In the past 30 races over two-plus seasons, he has five wins. Pagenaud has six and Power five. Only one other driver has as many as three (Bourdais).
Rahal also became the first driver this season to win after leading at the halfway point of a race.
Both races this weekend were relatively clean, although they were as fiercely competitive -- behind Rahal, that is.
Sunday's race was run with only the one caution flag, and there were only a few incidents drawing the attention of the stewards. One of those involved No. 2 starter Ryan Hunter-Reay.
On Lap 8, Hunter-Reay and Helio Castroneves got in a tussle resulting in Hunter-Reay's right-front wing slicing through Castroneves' left rear tire. Castroneves' car slowed, and it wasn't long before Hunter-Reay's did, too.
Mikhail Aleshin fought his way around Hunter-Reay before the latter decided he needed to pit for a new front wing assembly.
The last caution was for James Hinchcliffe, whose car stalled on the track. As workers went to retrieve that car, Spencer Pigot's car erupted in smoke, leading officials to stop the race to preserve the remaining laps.
NOTES: Takuma Sato won the pole during the morning session in a track-record time of 1 minute, 13.6732 seconds. Graham Rahal had set the mark in Saturday morning's qualifying session at 1:13.9681. ... Sato's pole was only the sixth of his career and his first since the same race in 2014. ... Mexican driver Esteban Gutierrez, who has Formula One experience, debuted this weekend and finished 14th in Sunday's race. He was Sebastien Bourdais' replacement after the Frenchman suffered pelvic fractures and a broken hip last month in qualifying for the Indianapolis 500 at Indianapolis Motor Speedway.