Bruce Anstey sealed his ninth victory at the Metzeler Ulster Grand Prix after a dramatic final lap in the opening Supersport race at Dundrod.

The Kiwi had been locked in a duel with Tyco Suzuki's William Dunlop and a thrilling finale seemed in prospect until the GSX-R600 machine expired.

Anstey was left in total control and went on to take the win from Northern Ireland's Lee Johnston in a comfortable second place on the Pirtek Honda, 6.441 seconds in arrears with Guy Martin on the second Tyco Suzuki a lonely third, 18.757 seconds behind the winner.

The race had been red-flagged earlier in the day after an incident involving three riders, none of whom were reported to have sustained serious injuries.

Michael Dunlop on the MD Racing Honda and Milwaukee Yamaha's Ian Hutchinson both retired from the race.

Ivan Lintin finished in fourth place with James Cowton - who won the Lightweight race by half a minute on his 250cc Yamaha - taking fifth and Russ Mountford completing the first six.