American Ben Spies completed a double on home soil to close in on FIM Superbike World Championship leader Noriyuki Haga.

The Yamaha rider, who yesterday broke the 18-year-old record of compatriot Doug Polen by claiming a seventh consecutive pole position, triumphed in a disrupted first race then dominated from start to finish to make it a perfect race day.

Spies stormed away from the field in race one after a red flag brought a halt to proceedings on lap seven.

The race had to be stopped temporarily when Australian Karl Muggeridge crashed and his Suzuki bounced back onto the track.

Officials decreed the final result would be decided by the aggregate times from the opening five laps - the only ones completed before the incident - and the 11 that followed when racing could resume.

Spies was four seconds ahead at the time of the red flag and had extended that to almost 10 seconds when he took the chequered flag ahead of Spaniard Carlos Checa.

Italy's Michel Fabrizio, who went into the weekend only six points behind second-placed Spies in the overall standings, claimed third, a further three and a half seconds back. Runaway championship leader Haga could only finish ninth.

The top-placed Briton was Jonathan Rea in fifth, while Leon Haslam came home 10th.

A second victory proved more straightforward for Spies, who led from pole to flag to complete his sixth win and second double of the season.

Fabrizio put up a good fight, keeping Spies in his sights for most of the race, while the battle for third provided most of the excitement.

Rea eventually prevailed after resisting pressure from a succession of riders, including Haslam, who crashed out on the final lap while trying to overtake his Honda counterpart.

Max Biaggi therefore finished fourth for Aprilia ahead of Ryuichi Kiyonari while Haga completed a disappointing weekend by trailing in eighth.