Valentino Rossi broke Giacomo Agostini's all-time premier-class win record by claiming his 69th MotoGP victory during atrocious weather conditions at the inaugural Indianapolis Grand Prix on Sunday.

The remnants of Hurricane Ike had been battering the circuit since lunch time, when heavy rain and winds hit the Indiana venue, forcing Race Direction to postpone the preceding 250 race.

However, a break in the storm allowed the MotoGP race to start at its allotted time, albeit on a soaking wet track, and it didn't take long for the torrential rain and gusting winds to return...

Rossi dropped from pole to fourth at the start of the planned 28 laps, then surrendered another place to Fiat Yamaha team-mate Jorge Lorenzo. Thereafter, Rossi found his rhythm and made his way back past reigning world champion Casey Stoner, Lorenzo and Andrea Dovizioso to sit second behind home hero Nicky Hayden by lap six.

Passing Hayden was no mean feat and it took Rossi eight laps to finally overtake the late-braking American, whose Repsol Honda seemed to have the edge on Rossi's M1 along the straights.

"It was an amazing race and a great battle with Nicky," said Rossi. "I always enjoy racing with Nicky and it was like three, four years ago when we did a lot of great battles.

"Nicky grew up very close to me because his first year [in MotoGP] was as my team-mate at Honda. I remember him coming first time from the US, and he was very desperate. I say Nicky, Nicky, quiet, quiet!" smiled Rossi. "It is a bit different here compared to US. But he is always strong and hard to overtake because he is very strong in braking.

"So we stayed together very close for many laps. Nicky is very wide, very aggressive but also very clean. So I enjoyed the fight. Then, when I got in front of him, I was a bit faster."

But Hurricane Ike wasn't finished with Indianapolis and on lap 16 of 28 it started to rain heavily once again, accompanied by strong gusts of wind which made riding perilous - even for a seven time world champion.