Father and son co-trainers Dave and Scott Brunton dealt a blow to Tasmania's top stayer Geegees Blackflash with Prevailing who upset him in the $225,000 Launceston Cup.Hobart Cup winner Geegees Blackflash was going for his sixth straight win from as many starts this preparation and was trying to set a modern-day weight-carrying record with 60kg in the Group Three 2400m feature.Prevailing had to be paid up as a late entry after Dave Brunton omitted to enter the Secret Savings five-year-old.The Br

Father and son co-trainers Dave and Scott Brunton dealt a blow to Tasmania's top stayer Geegees Blackflash with Prevailing who upset him in the $225,000 Launceston Cup.

Hobart Cup winner Geegees Blackflash was going for his sixth straight win from as many starts this preparation and was trying to set a modern-day weight-carrying record with 60kg in the Group Three 2400m feature.

Prevailing had to be paid up as a late entry after Dave Brunton omitted to enter the Secret Savings five-year-old.

The Bruntons saddled up last year's runner-up White Yard, which was the closest they'd got with two previous runners.

Jockey Peter Mertens made a lightning move on Geegees Blackflash ($3.90) from fifth at the 900m and at the 800m he was in front of his eight rivals.

He kicked away in the straight but the big weight took its toll in the closing stages with Prevailing ($10.40), ridden by Victorian-based Anthony Darmanin and carrying six kilos less than the topweight, getting up to score by a neck.

The Patrick Payne-trained Fieldmaster was sent out $3.40 favourite before finishing a length away third.

"That's an awesome thrill," Scott Brunton, whose mother Julie is one of the owners of Prevailing, said.

"I could have shot dad when he forgot to nominate him but the owners were really understanding and we paid the late entry fee to put him into the race."

Prevailing has now raced 21 times for eight wins and six placings and the first prize of $135,000 was more than $50,000 more than the $81,660 he'd earned in the past.

Brunton said the stable had sent the gelding to Victoria for a preparation on the mainland but the horse fretted and didn't fire in his races so he was returned to Tasmania.

"I don't think we would ever take him away from the beach, he was an absolute reptile when we took him over to Bevan Laming's," he said.

"But I think that made him into the horse he is."

While it was a career highlight for Darmanin, it was the first defeat Mertens has suffered in six rides on Geegees Blackflash.

"He was gallant in defeat," Mertens said.

"The pace was too slow early. He tried to hold on but with the 60kg it was too hard."

Prevailing had been racing in weaker company and at his previous outing had won a Benchmark 78 over 2100m at Launceston carrying 59kg, but he measured up with the five-kilo weight drop to the minimum in the Cup.

The field was reduced to nine runners after the scratching of Sea Galleon on race morning.

The Rosehill Christmas Cup winner was found to be lame after an early morning track gallop.

That followed the scratching of New Zealander Roi D'Jeu on Monday with a strained tendon, while the Darren Weir-trained Keep Control came out on Tuesday with a swollen fetlock joint.