Will Power of Australia won IndyCar's Sao Paulo 300 on Monday, a day after the race was postponed because of heavy rain on the streets of South America's biggest city.
Graham Rahal was second and Ryan Briscoe third on a wet track at the 2.5-mile, 11-turn Anhembi temporary street circuit.
Power, who started from the pole position, drove to victory for Penske after Japan's Takuma Sato had to pit for fuel with about 10 minutes left. Sato led for 23 laps but finished eighth after his gamble failed.
Power finished 4.672 seconds ahead of Rahal and 7.904 in front of Briscoe. It was his second win in four races this season, giving him the points lead going into the Indy 500 later this month. He has started from the pole in all four races.
''It was an awesome race,'' Power said. ''There were so many different track conditions. It was a matter of keeping calm and getting past most people without making mistakes.''
Power fell to the back of the field after pitting early while Sato and others stayed out despite an early yellow flag instructing drivers to slow down. Despite the track being still extremely wet in places, Power was able to quickly move back to the front.
''The conservative thing was to come in,'' Power said. ''It was a good strategy (to stay out).''
Former drivers' leader Dario Franchitti recovered from a crash to finish fourth in the race, which ended at the two-hour limit with only 55 of the scheduled 75 laps completed.
Franchitti now trails Power by 14 points.
The race restarted with 14 laps completed after torrential rain on Sunday had made track conditions unsafe, forcing it to be stopped twice and eventually postponed.
Last year's inaugural Sao Paulo 300 also was affected by severe weather and ended before its scheduled 75 laps.
The cars returned to a dry track on Monday but it started raining hard again as soon as the green flag dropped, forcing all cars to immediately go to the pits for wet tires.
Drivers still struggled to stay on track and visibility remained poor because of water spraying from the cars.
Power nearly lost control a few times and came close to touching the wall at the exit of a corner, while Ryan Hunter-Reay, who started second, spun out and crashed the back end of his car. He finished 18th.
The first yellow flag to slow down came when Sebastien Bourdais missed a turn and went straight into a tire barrier. At the restart, Sato passed Power to take the lead going into the first chicane.
Franchitti was one of the many drivers having trouble entering the first corner with several others being forced into the runoff area. Danica Patrick, Alex Tagliani, James Jakes and Justin Wilson also had problems on the slick track.
Venezuela's E.J. Viso had a good run on the wet and was up to second before receiving a drive-thru penalty for repeatedly blocking Marco Andretti. Viso dropped to ninth after the penalty and eventually finished 13th, one position ahead of Andretti.
The next four IndyCar races will be on oval tracks, beginning with the 100th running of the Indy 500 on May 29.
