Jonathan Rea extended his lead at the top of the World Superbike standings to 54 points by finishing second behind Chaz Davies in race one at Laguna Seca.
Ducati rider Davies took his fourth win of the season at the California circuit despite still suffering the effects of a crash at Misano three weeks ago.
The Welshman has been recovering from a spinal injury and a thumb fracture.
Davies finished 1.2 seconds ahead of Rea, with pole setter Tom Sykes third and Italy’s Marco Melandri fourth.
The three British riders were involved in a three-way battle at the front, although Yorkshireman Sykes fell off the pace in the latter stages of the 25-lap race.
Northern Irishman Rea maintains his record of having achieved a podium finish on each of his visits to Laguna Seca since 2014, the double world champion having shared a win apiece with Kawasaki team-mate Sykes last year.
Milwaukee Aprilia rider Eugene Laverty crashed with 15 laps remaining of the first race of the eighth round of the championship, with England’s Alex Lowes also coming off.
“It was important to bounce back with a win, although my priority today was just to finish the race and maybe get a podium. Once I hit the front I didn’t want to overstep the mark with the front end,” said Davies after the 24th victory of his career in the series and his third at the American track.
Rea, winner of eight races this season, added that Davies “deserved a lot of credit for coming back from our crash at Misano”.
“In the first part of the race I was sitting comfortably and thought that I had enough pace to pull away but then I couldn’t get grip off the rear and couldn’t pull out of the corners the way I wanted to.”
After Sunday’s race at the same venue, the championship takes a five-week break until the next round in Germany.