A dejected John O'Shea could offer no excuse for the disappointing run of Sea Siren in the Hong Kong Sprint at Sha Tin on Sunday.

Sea Siren, a triple Group One winner in Australia this year, finished ninth behind Japanese star Lord Kanaloa who now boasts a record of 12 starts for eight wins and four placings.

Neither the trainer nor jockey Jim Cassidy could explain the run from a mare who had given every indication she was fit and well going into the race.

"She's never run like that in her life," O'Shea said.

"I've got no idea what happened."

Cassidy said he'd been unable to get a position in the first 300m, but it hadn't affected Sea Siren's chances at the end of the 1200m.

"She was three deep early, but it didn't matter.

"She only went to the corner."

Sea Siren jumped on terms with the field, but so did several of the six runners drawn inside her.

Cassidy managed to squeeze into a position two off the fence before the turn but was then obliged to ease wide again in an attempt to make ground.

After making a fighting attempt to pick up ground in the straight, Sea Siren weakened without ever looking like a placegetter.