Tough filly Rare Occurrence confirmed her rating as a Doomben specialist when she upset older horses in the Swire Shipping Plate on Saturday.

Backed from $21 into $12, Rare Occurrence wore down the favourite Invincible Express ($4.20) to score by a length.

Rare Occurrence has now won four of her eight starts at Doomben.

Trainer Stu Kendrick could have started Rare Occurrence earlier since she returned from a spell but waited for a Plate race at Doomben.

"She loves the track and under the Plate weight scale she carried only 51 kilos with Tiffani Brooker's claim," Kendrick said.

"She has always shown ability and now we can chase black type with her.

"If she can get into some of the fillies and mares stakes races it would be very good."