Scott Dixon finished sixth in the second race of the Detroit Grand Prix but has maintained his lead in the IndyCar top driver standings.
Graham Rahal completed a doubleheader sweep on Monday as his Honda-power car finished 1.17 seconds ahead of Josef Newgarden's Chevrolet, a day after getting to the chequered flag six-plus seconds ahead of the competition.
Dixon, who was second in the first Detroit race on Sunday, trailed behind Will Power, Takuma Sato and Simon Pagenaud in the second event.
But Dixon accumulated enough points to preserve his overall lead, moving up to 303 points - eight ahead of Brazil's Helio Castroneves, who was seventh on Monday. Sato holds third place on 292 points and Detroit doubleheader winner Rahal is now sixth with 251.
Rahal pulled away for the victory after a single-file final restart with two laps to go in the 70-lap race on Belle Isle course.
The 28-year-old American 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 Dixon pulled off the feat four years ago in Toronto.
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.
On Saturday, Rahal, from New Albany, Ohio, became the first American to win in Detroit since Michael Andretti in 1996. He has six career victories, five in two-plus seasons.
Rahal told a trackside interviewer it was "a great weekend for the team".
"To get two wins is pretty special for me."
He said he had "no clue" why he was so successful in Detroit. "I don't know and I don't care, as long as the magic keeps going, I have no problem.
"I hope we get more weekends like this, but they don't normally come this easy."
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.
Sato, the Indianapolis 500 winner, earned the pole earlier in the day and finished fourth with his Honda-powered car for Andretti Autosport.