Reigning six time MotoGP world champion Valentino Rossi took on American grand prix legends Kenny Roberts, Wayne Rainey and Eddie Lawson during a Superkart 'exhibition' at Laguna Seca on Thursday.

The quartet, who have won a combined total of 16 premier-class world championships since 1978 - three for Roberts and Rainey, four for Lawson and six for Rossi - drove the 250cc Yamaha two-stroke karts for two fast laps around the undulating Californian circuit, which will host Sunday's US Grand Prix.

Although it was not officially meant to be a race, it unsurprisingly turned into one - although the drivers couldn't agree who had started it - with Rossi coming out on top by around 15 seconds over the Americans, who crossed the line in a formation finish.

“I am happy because now it is possible for me to say I beat Wayne Rainey, Kenny Roberts and Eddie Lawson!” smiled Rossi. “To share the track with these great names from the past was fun and important."

Superkarts, which feature more bodywork than a 'normal' kart, including a rear wing, can lap the 3.601km track just a couple of seconds slower than the MotoGP bikes.

“Honestly I was bit nervous about the Superkarts before because I know how fast these things are!” said Rossi, who finished fourth in the 1991 Italian Junior Go-Kart Championship.

“I sometimes drive one in Italy with friends, just for fun, but I know that Kenny, Eddie and Wayne like to race and they're quite serious! Also this isn't the easiest track... Anyway, it was great fun and I enjoyed myself a lot.

“The kart is quite incredible; the gearbox is very good and in the hard braking areas it's really impressive. It feels very fast and it's possible to have a lot of fun.

"I'm looking forward to getting back on my bike tomorrow however!” added the Italian, who won his 100th grand prix last weekend at Assen.

See below for more pictures from the event.