John McGuinness secured his 16th TT success by winning the six-lap Superbike TT in perfect conditions.
The Honda rider from England came home 56 seconds ahead of runner-up Cameron Donald, with Gary Johnson third.
Keith Amor, Ballymoney's Michael Dunlop and Dan Stewart completed the top six leaderboard in the TT opener.
New Zealander Bruce Anstey led for part of the race but retired on lap three after setting the fastest lap of the race at 131.05mph.
At the end of lap one McGuinness led by 0.5 seconds from Anstey, with Johnson third and Guy Martin fourth.
Anstey assumed the lead after the second circuit, thanks to his lap at over 131mph, with Martin up to third and Johnson fourth.
A quick pitstop by McGuinness saw him move into the lead again and then Anstey retired his Padgetts Honda at Quarry Bends.
Morecambe man McGuinness led Martin by 19 seconds after lap three and lap four but Relentless TAS Suzuki rider Martin parked his machine at Hillberry on the fifth lap.
Martin's retirement allowed Donald to take second, with Johnson a further 10 seconds behind the Australian after being hit with a 30-second time penalty for exceeding the 60mph pitlane speed limit.
Michael Dunlop finished fifth despite encountering major problems with a rear wheel change at the end of the second lap.
William Dunlop was seventh on the Wilson Craig Honda, James Hiller eighth and Adrian Archibald ninth.
Michael Rutter and Daniel Kneen retired on lap one and Conor Cummins on lap four.
"I'm really delighted, I thought I may never win a Superbike race again," said McGuinness after clinching his sixth victory in the TT Superbike race/
"It was shaping up to be a really close race, but then Bruce went out.
"I really pushed hard on the third lap and then brought her home and didn't really make any mistakes.
"It was a good race and I must pay tribute to my pit team - they were superb as always.
"There were loads of people out there and I thank them all for their support."
Dungannon rider Ryan Farquhar sustained a broken rib in a crash during Friday night's final practice session.
Farquhar came off his Kawasaki machine at the Keppel Gate section of the circuit.
He remains in hospital with minor injuries and missed Saturday's race, while it is unclear if he will race next week.
Meanwhile, Austrian Klaus Klaffenbock won his third TT with success in Saturday's Sidecar Race A.