Gibraltar Girl has prevailed in a three-way photo-finish at Randwick with the well-supported favourite I Thought So out of the picture.

Stewards questioned Tim Clark at length about his ride on the David Pfieffer-trained I Thought So who was backed late from $2.40 to $2.15 but finished sixth after going wide at the start.

The head-on view showed I Thought So heading left out of the barrier before Clark managed to steer him back and tack on to the field.

He then over-raced when the tempo slackened and stewards agreed the jockey had done what he could which was no solace to the colt's disappointed trainer.

But there were smiles all round for the winner who is trained by Peter and Paul Snowden and could head to next month's Scone carnival.

The filly is raced by Greg Kolivos who enjoyed his biggest successes with champion juvenile Pierro, winner of the 2012 two-year-old triple crown.

"I'll talk it over with Peter Snowden but she could head to the fillies' stakes race at Scone," Kolivos said.

Gibraltar Girl ($8) beat Tessera ($7.50) by a short half head with Calabasas ($5.50) in the middle of the pair another nose third.

"I was able to get the drag into the straight, peeling off their backs and she was too good," her jockey Tye Angland said.

The winner has been to stakes level twice before, finishing third in the Listed Mode Plate at Eagle Farm in December and fifth in the PJ Bell Stakes earlier this month.