Low cloud over the mountain brought frustration for the competitors, as they faced a 75 minutes delay, but Anstey, the Kiwi who enjoyed maiden success in the 250cc race, was quickly disputing the lead with Lougher.

Anstey pitted after the first lap, needing to change his visor, but, the stop was problematic, costing him vital time, while Lougher, maintaining his pace, was extending his advantage, with Jim Moodie moving into second place.

Lougher, with the race's fastest lap at 120.25mph, was always in charge, with Anstey slotting back into second place, despite Moodie making a lightening stop to re-fuel.

"I really enjoyed that one - I knew that I could go well, but, I was just a bit concerned when there were a few spots of rain towards the end of the second lap, and I did not want to have to push too hard on the final lap," said Lougher.

Shaun Harris finished third, 13 seconds down on Archibald, but some 19.5 seconds ahead of Honda's Adrian Archibald.

600 Production TT result (three laps 113.19 miles): 1 Ian Lougher GB (Suzuki) 57m 08.4s - 118.85mph; 2 Bruce Anstey NZ (Suzuki) 57m 36.9s; 3 Jim Moodie GB (Yamaha) 57m 55.4s, 4 Shaun Harris GB (Suzuki) 58m 08.6s, 5 Adrian Archibald GB (Honda) 58m 28.1s, 6 Richard Britton GB (Suzuki), 7 58m 35.2s, 7 David Jefferies GB (Suzuki) 58m 47.0s, 8 Gordon Blackley GB (Honda) 58m 58.0s, 9 Roy Richardson GB (Suzuki), 10 John McGuinness GB (Honda) 59m 10.3s.