Rain, usually a race driver's enemy, was Michael Andretti's ally Sunday in Miami.
"It was one of those days when everything just went our way," Andretti said after running away from the rest of the field during a downpour to win the Nissan Indy Challenge at Tamiami Park.
The winner, handling the wet 1.784-mile, 9-turn circuit with aplomb, led second-place Al Unser Jr. by 56.045 seconds when the race was red-flagged nine laps before the scheduled end.
"When it was dry, it was nip and tuck with Al," Andretti said. "I was praying for rain.
"My car was running real well in the rain. It was real balanced, and I could get the power down. It wasn't bad at all."
Unser, the defending Miami race champion, lost the left-front wing of his March when he bumped with a slower car just after the rain intensified at about lap 66.
Andretti, who led from lap 49 until the race was stopped at the end of lap 103, averaged 94.873 m.p.h. and collected $67,410.
Geoff Brabham of Australia, the only other driver on the lead lap at the end, made it a sweep of the top three spots by second-generation Indy-car racers.
Andretti is the son of Mario Andretti, who finished fourth on Sunday. Unser is the son of four-time Indianapolis 500 winner Al Unser, and Brabham's father, Jack, is a two-time Formula One champion and the man who drove the first rear-engine car at Indianapolis.
Gerhard Berger of Austria brought Ferrari back to the victory circle, winning the Japan Grand Prix at Suzuka, Japan, by about 17 seconds.
Berger, who is 28, the same as the number on the side of his blood-red Ferrari, took the pole position for the 51-lap event, got an early lead and never looked back, losing the lead only briefly for a pit stop.
It was the second victory in 51 Grand Prix races for Berger, who lives in Worgl, Austria. He also won the 1986 Mexican Grand Prix.
Berger completed 51 laps of the 3.64-mile circuit in 1 hour 32 minutes 58.072 seconds, averaging 119.565 m.p.h.
Ayrton Senna of Brazil was second in a Camel Lotus-Honda in 1:33:15.456. Stefan Johansson of Sweden was third in a Marlboro McLaren-TAG in 1:33:15.766, with Michele Alboreto fourth in the second Ferrari.
Fifth was Thierry Boutsen of Belgium in a Benetton-Ford. Local favorite Satoru Nakajima was sixth, receiving one world championship point.