Fun Fact dented the reputations of several Queensland Derby contenders when he led throughout to win the Group Three Grand Prix Stakes at Eagle Farm.

Ridden by Michael Cahill, Fun Fact ($19) scored by a length from Angel Of Heaven ($10), the lone filly of the field, with Home Made ($71) a short neck away third.

Trainer Bjorn Baker admitted he was concerned when Fun Fact was four lengths clear of the field at the halfway stage of the Grand Prix.

"I thought he might've been going a bit keen and halfway down the straight I thought we were in trouble," Baker said.

"He's bred to get over a trip and the main aim was to hopefully qualify him for the Magic Millions staying race next January so we've got to look at the Derby in a fortnight.

"He's had 10 runs this prep so we might as well keep him going."

Fun Fact continued the dream run of jockey Michael Cahill who won the Group One Doomben 10,000 aboard The Bostonian on May 11.

Cahill was taken aback by Fun Fact's eagerness to race as he was completing his preliminary.

"Going to the barriers he took hold of me and when the gates opened he sprung out and there was no way he wasn't going to lead," Cahill said.

"I had that much horse underneath me when I got the 1000-metre mark I thought I'm just going to disadvantage him if I try and slow him any more.

"He's a very fit horse and a real stayer."

Fun Fact firmed from $51 to $11 for the Group One Queensland Derby (2400m) at Eagle Farm on June 8.

By contrast Lord Arthur, the $3.40 favourite in the Grand Prix, drifted from $9 to $15 with TAB Fixed Odds for the Derby after he finished a disappointing 10th.

Lord Arthur's stablemate Bobby Dee also failed to make an impact, finishing eighth.