Defending champion Jonathan Rea held off Kawasaki team-mate Tom Sykes to win a thrilling first race at the eighth World Superbike round in Misano, Italy.
Northern Irishman Rea, 29, was 0.09 seconds ahead of English rider Sykes, 30, to extend his title lead to 61 points before Sunday's second race.
Dutchman Michael van der Mark finished third, 3.093 seconds behind Rea.
Wales' Chaz Davies recovered after he was caught up in Lorenzo Savadori's first-lap crash to finish fourth.
Davies ended the race 5.878 seconds off the pace.
After winning five of this season's opening eight races, Rea had been without a victory in six starts.
His success made it 15 podiums from as many starts for the Northern Irishman.
The Isle of Man-based rider secured his maiden win in the global series at Misano in 2009 and has gone on to add a further 34 triumphs since then.
Huddersfield's Sykes has won four times this season and took victory in both races at the previous round at Donington Park.
After this weekend's action in Italy is complete, the competitors will race next at Laguna Seca in the United States on 10 July.
That will be followed by an eight-week break, before the final run of rounds which takes in Germany, France and Spain, before concluding in Qatar on 29 and 30 October.
|World Superbike Championship 2016|
|1. Jonathan Rea (GB)||Kawasaki||318|
|2. Tom Sykes (GB)||Kawasaki||257|
|3. Chaz Davies (GB)||Ducati||244|
|4. Michael van der Mark (Ned)||Honda||157|
|5. Davide Giugliano||Ducati||149|
|6. Nicky Hayden (USA)||Honda||136|