Northern Ireland’s Jonathan Rea stretched his lead at the top of the World Superbike Championship standings to 59 points with a commanding race two victory at Laguna Seca.
Rea, who started from the third row of the grid, took less than three laps to hit the front as he and Kawasaki team-mate Tom Sykes took control almost from the off with 2.88 seconds separating them on the line.
Race one winner Chaz Davies was third, with fellow Ducati rider Marco Melandri fourth for the second time this weekend.
Ireland's Eugene Laverty finished in sixth place on his Aprilia with Alex Lowes ninth for Yamaha.
Reigning champion Rea's win - his ninth from 16 races this season - came courtesy of a flying start as he followed Sykes past Italy's Melandri, who had started on pole, before slipping past his team-mate in a dominant performance.
Davies was unable to match the pace of the Kawasaki's as he fought his way through the pack to lead the rest of the field home.
The win took Rea to 341 points with Sykes second on 282 and Davies, who won on Saturday on his return from the fractured vertebrae and bruised thumb he suffered during the opening race in Misano last month, third on 226. Laverty is in tenth place in the championship.