Rossi wins rain-shortened Indy MotoGP

INDIANAPOLIS (Reuters) - World championship leader Valentino Rossi won the rain-shortened Indianapolis Grand Prix on Sunday to notch his fourth straight win and tighten his grip on the MotoGP title.

Italian Rossi, unbeaten since his victory at the U.S. Grand Prix in July, claimed victory when heavy rains and violent winds swept across the famed Brickyard bringing out the red flag with seven laps to run and giving the seven-times world champion a record 69th career MotoGP win.

"These were the worst conditions of my career," Rossi told reporters after capturing the first motorcycle race at the Indianapolis Motor Speedway since 1909. "There was lots of water and wind was very bad. I was hoping for the red flag."

Local favorite Nicky Hayden of the United States was second while Rossi's Fiat Yamaha team mate Spaniard Jorge Lorenzo finished third.

Defending champion Casey Stoner of Australian finished fourth, allowing Rossi to take a commanding 87-point lead on top the standings with four races remaining.

Starting from pole, Rossi surrendered the lead to Stoner on the second lap but stayed in the battle at the front finally reclaiming top spot from Hayden on lap 14.

Rossi then grimly held on for his seventh win of the season as conditions worsened.

"With this wind, it's literally unrideable," Stoner told reporters. "The rain wasn't a problem in the race; it was actually the wind issues.

"It became very dangerous. It was ridiculous. The safest option was to stop.

"We're happy with the race today, but I would rather go home in one piece. Even in dry conditions, I don't think it's safe (because of the wind).

"It is literally unbelievable. I don't think you can keep your bike online, and I think there would be a few nasty crashes."

Local media reported that an infield tent collapsed during the storm sending two spectators to hospital with injuries.

Rain forced officials to cancel the 250cc race while Spaniard Nico Terol claimed his first career win with a victory in the 125cc event, which was halted after 16 of 23 scheduled laps.

(Writing by Steve Keating in Toronto; Editing by John Mehaffey)