The Chris Waller-trained Foreteller has delivered a Group One upset during the official start to the Sydney autumn racing carnival on Saturday.

The imported galloper started one of the outsiders in the Ranvet Stakes at Rosehill before beating the three-year-old Fiveandahalfstar to win the weight-for-age race.

His victory gave veteran jockey Jim Cassidy the 96th Group One win of his career but his first for Waller, Sydney’s premier trainer.

“Chris has been marvellous to me over the past two or three years,” Cassidy said.

“I don’t ride a lot of work for him but I do a bit of work at the barrier trials to keep my eye in and pick up a few rides here and there.”

Foreteller raced slightly worse than midfield but worked his way through the pack to be the first horse chasing the leader Fiveandahalfstar in the straight.

Fiveandahalfstar, who had beaten Foreteller convincingly when they met in the Australian Cup at Flemington earlier this month, set up a four-length lead at the 300m.

But he was wound in by Foreteller with 75m to go before holding on for second ahead of minor placegetter Maluckyday.