Even Wagga trainer Peter Morgan conceded he was surprised by the first-up victory of Zarlu at Murrumbidgee Turf Club on Thursday.
Zarlu produced a big first-up performance to take out the feature race, the Rodney Parsons OAM Handicap (1400m).
Zarlu was sent out the extreme outsider of the field at $71 and came from last in the straight, unleashing a blistering turn of foot to sweep past his rivals.
The nine-year-old stormed down the outside to score by two lengths, from Son Of Spartacus ($11.00), with Spunlago ($2.35) a further half length back in third.
Morgan conceded the feature win first-up had caught him by surprise.
"It did. He's come in so when it rains he's in business," Morgan explained.
"He didn't wait for the rain though."
Zarlu had never previously won at 10 first-up attempts going into Thursday's feature.
Morgan said the horse had been working well but had nothing particular picked out for him.
"He has been working good," he said.
"He's the best mud runner in the district so I was getting him ready for the wet tracks.
"I thought he would be giving them six or eight lengths coming into the straight but today he was only giving them two. That made a big difference."
It was Wagga apprentice jockey Stacey Metcalfe's first win on Zarlu after seven rides. She had previously finished second on the horse twice, both in the metropolitan arena.
Morgan also had Bulala run in the trial, after the last race at Wagga.
It was his second trial within a week and he will go to the $150,000 Country Championships heat at (1400m) Albury on Saturday week first-up.
He is unbeaten from four first-up starts and Richard Bensley has been booked for the ride.
Meantime, the powerful Hayes-Dabernig team enjoyed a winning double at Wagga on Thursday.
It was the stable's second winning double at Wagga at the past three meetings.
Like last time, talented Victorian apprentice Lewis German rode both winners.
Toorsinaa ($3.90) proved too tough for her rivals in the Private Marquee On Cup Day 2YO Maiden Plate (1000m), before German produced a brave ride to win the Champagne Bar On Cup Day Class One Handicap (1200m) on Inglesias ($4.80).
Stable foreman Eric Broad was not surprised by Toorsinaa's maiden win.
"She ran really well. We were disappointed, we expected her to nearly win first up," Broad said.
"With race experience, we expected her to go very close. She's still a bit green but she fought back well to win it.
"Hopefully she progresses into city class."
It was the stable's only two runners for the day.