Lacerate, a colt by group 1-winning Sydney sprinter Charge Forward, was the fastest winner at Thursday's first official set of two-year-old trials.

He sped over the Mowbray 800m course in 47.69 seconds while scoring by a head over Wheeling (a Holler colt trained by Graeme McCulloch).

"He was very professional and did everything right," Hamer said. "He was probably getting a bit tired at the finish but other than that he was good."

Hamer said Lacerate had been in and out of work several times.

"This is about his fourth prep. and he's been back in work about eight weeks," the trainer said.

"He'll now go to the first two-year-old race of the season (in Hobart on November 15) if he pulls up all right."

In one of the biggest turnouts in recent years, 29 two-year-olds contested five trials.

The other winners were Fighting Styx (trained by Patrick Dargan) in 48.03, Coeur De Lyon (Cameron Thompson) in 48.14, Gee Gee Enuf Speed (Team Wells) in 48.60 and Geegee Lucky Jess (Stuart Gandy) in 48.88.

Victorian trainer John Nicholson has plundered plenty of Tasmanian prizemoney over the years and he is in search of more with Tasmanian Derby winner Micton Mouse.

The three-year-old will contest a heat of the Globe Derby Stakes at Mowbray on Sunday night attempting to qualify for the $50,000 final the following week.

Although he hasn't won a race since he led all the way in the Derby in March, Micton Mouse is drawn to find the front again and should be hard to run down.

The gelding was bred by Michael and Toni Laugher of Westbury and the family remains in the ownership.

He has drawn the second heat of the Globe Derby which doesn't look particularly strong, with Kivik (61) and Micton Mouse (60) the highest-rated runners.

The first heat has more depth with Colby Sanz (67), Kohanah (64), Watchmylips (61) and Kosimo (58) appealing as the main chances.

The second heat is the pick of the two Bandbox qualifying divisions.

Blame It On Me will be out to continue a successful comeback from injury but can expect strong opposition from Tasmanian Oaks winner A Spanish Dance who is resuming.

Sunday's quality 10-race meeting also includes a free-for-all featuring Ignatius, Call Me Hector and Izaha.

Carrick harness trainer Craig Van Dongen has been suspended for 12 months over a positive cobalt swab.

However he's had six months of the penalty wholly suspended for a year.

The Van Dongen-trained Shady Story tested positive after winning at Mowbray in July.

He was disqualified from the race and the placings amended to Heza Sport 1, Auntie Connie 2, Gauci 3.

The trainer has indicated he will not appeal.

Thoroughbred trainers Graeme McCulloch and Chester Roach were fined $500 each over a saddlecloth mix-up at Mowbray on Wednesday night.

Windrider and Wookiee left the mounting yard wearing the wrong numbers and the mistake wasn't detected until seconds before the start.

The red light was flashing and the last horse being loaded when someone finally reacted to an alert from racecaller Colin McNiff that there was problem.

There was a lengthy delay as the horses were unsaddled and the numbers changed.

Chief steward Scott Quill said an unfortunate set of circumstances began when Windrider's jockey Kyle Maskiell was late weighing out.

"Everything became rushed and one thing led to another," he said.

"The trainers didn't check the numbers on their horses as they came into the mounting yard - one of which covered by a towel due to the rain - and the stewards didn't pick up on it either.

"They checked the brands on the horses to establish their identity but didn't lift the towel (on Wookiee) to check the number.

"Our guys have been counselled to make sure it doesn't happen again but the ultimate responsibility lies with the trainer to present their horses wearing the right number."