DETROIT -- Will Power gave Roger Penske and Chevrolet what they desperately wanted by winning the first of two races at the Detroit Grand Prix.
"On his home track and in Chevy's backyard, it's a perfect day," Power said Saturday. "If we can do it again tomorrow, it'll be even better."
Power finished 0.3308 seconds ahead of Graham Rahal on the bumpy, 13-turn, 2.36-mile street circuit on Belle Isle.
He started a season-worst 16th and took the lead for good with just more than 10 laps to go when he passed Ryan Briscoe.
"There's no way we thought we would come from 16th to win," he said. "But this is IndyCar and anything can happen."
The Australian held off Rahal to join Indianapolis 500 champion Ryan Hunter-Reay as the series' drivers with two victories through six races. Power pulled within three points of Hunter-Reay, IndyCar's points leader.
James Hinchcliffe of Oakville, Ont., finished in sixth place.
Power, who won IndyCar's season-opening race, has 23 career victories to break a tie with Emerson Fittipaldi and Tony Bettenhausen and to match Tommy Milton for 18th on the all-time list.
His latest victory was especially sweet for Penske and Chevy.
Penske had not won an open-wheel race in the area he calls home since Helio Castroneves finished first in 2001.
"It's sure a great piece of satisfaction for me to see this happen," Penske acknowledged.
And for Chevy, which sponsors the race, it was a good day after being relegated to watching Honda dominate the previous three races over the last two years in the shadow of its world headquarters.
"We swept the podium in 2012," Art St. Cyr, president of Honda Performance Development, said a few hours before Saturday's race. "We won both races last year, swept the podium in one race and had two of the three spots in the other race
"There are a lot of Chevy folks here, so you do walk around with your chest puffed out a little bit more."
After the 70-lap race, Honda had to settle for Rahal's second-place finish as its only driver on the podium. Rahal, whose only career victory was in 2008, had finished no better than 13th this year.
"It's a great day for us with the year we've had and the luck we've had," Rahal said.
Tony Kanaan was a season-best third followed by Justin Wilson and Castroneves, who was the pole-sitter and led a race-high 30 laps Saturday.
"I wish I could relax," Kanaan said "My mind is already going on what I have to do tomorrow."
Hunter-Reay, meanwhile, failed to follow up the biggest win of his career with a 16th-place finish. He was on the last lap, but did not make it to the finish line because he spun into a tire wall to end the race. He started 21st in the 22-car field because he brushed a wall on his second lap during Saturday morning's qualifying session.
"We had a rough day overall," Hunter-Reay said.
Simon Pagenaud and Mike Conway each won last year on Belle Isle and both lost their shot to win early Saturday.
Pagenaud damaged his front left suspension when he ran into the back of Power, leading to a yellow.
"I didn't even know where Pagenaud was," Power insisted.
Conway did not have any one around him when he appeared to understeer into a wall on Lap 15, putting the race under caution.
Both will get another shot to repeat at the Detroit Grand Prix on Sunday as part of IndyCar's first of three doubleheaders this season.
While Penske was thrilled with the victory after Castroneves was barely beaten by Hunter-Reay's Honda-powered car last Sunday at the Indy 500, he knew there were fewer than 24 hours to celebrate before the next race on Sunday.
"We all start from ground zero," he said.