World champion Nicky Hayden will be looking for another good performance at the US Grand Prix this weekend although he faces a tough challenge from Australia's MotoGP leader Casey Stoner.

Despite being the reigning world champion, 25-year-old Hayden is only ninth in the series standings with 73 points.

The American qualified sixth last year at the Laguna Seca event, but moved into the lead midway through the final and was never challenged.

Hayden, who has finished third in the circuit's last two races, was also the winner when the MotoGP made its American debut at Laguna Seca in 2005.

Practice was held yesterday at the Laguna Seca Raceway in the MotoGP class as well as in Superbike and Supersport classes, with qualifying for the MotoGP scheduled for today.

The championship race takes place tomorrow. MotoGP 125cc and 250cc division will not be held.

Consistent Stoner

Stoner, 21, who finished fifth last weekend in Sachsenring, Germany, has won five of his 10 races this season and has not finished lower than fifth.

He will be favoured again this weekend against a strong American contingent and will also try to make up for a disappointing result he had last year in the United States when he withdrew after a crash.

Stoner leads the overall standings with 196 points with five-times world champion Valentino Rossi second on 164.

Dani Pedrosa, of Spain, last week's winner in Germany, is third with 144 points, and American John Hopkins fourth on 101 points.

A victory earns a rider 25 points, with points reduced to one for 15th place.

The 32-lap race on the 11-turn, 3.6-kilometre Laguna Seca circuit takes place during the venue's 50th anniversary season.