John McGuinness set a new lap record on the Isle of Man

The pre-race favourite led from start to finish on a Yamaha to take the Formula One race ahead of runner-up Adrian Archibald from Northern Ireland.

Bruce Anstey from New Zealand was third in Saturday's curtain-raiser.

McGuinness set a record time for the 37.75-mile circuit with an average speed of 127.68mph.

Archibald, from Ballymoney, had a problem on the first lap with a loose front brake master cylinder but he later passed TAS Suzuki team-mare Anstry to take second place.

Dungannon rider Ryan Farquhar's challenge was effectively over on the first lap because of a loose rear shock absorber. He did rejoin the race but was never in contention for honours.

The event was the last Formula One race in the TT as it is to be replaced next year by a Superbike race.

"I could see Adrian's board and my board so I knew it was between us two," said McGuinness after his fourth TT triumph.

"I had a 20 second buffer but at every hairpin when we slowed down I coud hear him behind me so there was a little bit of pressure.

"If I had made a mistake Adrian would have been away."

TT Formula 1: 1 John McGuinness (Yamaha R1) 1hr 12 mins 13.2 secs; 2 Adrian Archibald (TAS Suzuki) 1hr 12 mins 31.8 secs; 3 Bruce Anstey (TAS Suzuki) 1 hr 12 mins 58.0 secs; 4 Jason Griffths (Yamaha R1) 1 hr 13 mins 20.3 secs; 5 Ian Lougher (Honda 1000) 1 hr 13 mins 27.7 secs; 6 Richard Britton (Suzuki) 1 hr 13 mins 53.1 secs.