Matt Dunn admitted he may have made an error in training Arrestar as a sprinter after the gelding won over 1600m at Doomben on Saturday.

Arrestar ($5) showed plenty of heart to beat Lady Lark ($5) by a neck with 2 1/2 lengths to Diomedes ($6.50) in the Furances @ Aquis Farm Handicap.

A flashy chestnut by Star Witness, Arrestar won his first start at Eagle Farm and Dunn set him for the Magic Millions 2YO Classic (1200m).

Arrestar eventually finished 12th behind Houtzen in the Magic Millions.

"We got him into the Magic Millions but in hindsight it probably wasn't the race for him," Dunn said.

"On his breeding you would think he is a sprinter but he ran a strong 1600 metres today and he should get at least 1800 metres."

Arrestar has proved a tough horse this campaign as he also had three starts in Sydney before returning north.

"Two of his runs in Sydney were good and he might make a more than handy horse," Dunn said.

Dunn had an extra reason to be happy as he celebrated his fifth wedding anniversary to his wife and main assistant Keira.

"How is it everyone remembers that date but me," Dunn joked.

Winning jockey Jim Byrne, who was second in last year's metropolitan premiership, is off to a flying start with his second win of the new season on Arrestar.

"We got a nice run and he showed plenty of fight in the straight," Byrne said.