Sydney premiership-leading jockey Brenton Avdulla' has been taken to hospital for X-rays on his right knee after a barrier mishap at Rosehill.

Avdulla has been on the crest of a wave this season, leading both the metropolitan and NSW premierships and claiming the VRC Oaks on Lasqueti Spirit.

But he came crashing down when Cottage acted up in the gates before Saturday's second race and both jockey and horse were late scratchings with mare kicking out at Avdulla .

Cottage also landed a blow on the favourite Dagny in the adjacent stall forcing that mare's withdrawal.

With the field for the Promaster Protection (1400m) reduced to eight, the Gerald Ryan-trained Girl Sunday ($9) took up the role of race leader with apprentice James Innes rating her to perfection.

And as new race favourite Dixie Chick ($4.40) was bearing down hard, Girl Sunday raised another effort to beat her by a short half-head.

"It helped us with Cottage out of the race. She was able to lead comfortably," Innes said.

Cottage's trainer John O'Shea said the mare would now go for a spell.

The incident could prove costly for Avdulla who was in the box seat for the Godolphin stable's plum rides with James McDonald standing himself down pending an investigation into a betting offence.