Leading jockey Craig Williams has been taken to hospital after a sad finish to the Listed Mornington Cup.

Williams had ridden the Godolphin visitor The Gold Trail into fourth place in Saturday's 2400m Cup when the stayer broke down as he began to pull up after the race, throwing the rider to the turf.

Initial reports suggested Williams was unconscious for a short time before he was transported to hospital for assessment, while The Gold Trail, trained by Englishman Charlie Appleby, was unable to be saved.

Locally trained gelding Tally gave Godolphin some consolation with his win, which earned the four-year-old a ballot exemption for the Caulfield Cup in October.

Andrew Mallyon was aboard Tally in his Mornington Cup success and the win continued a great weekend for his family after his sister Katelyn won her maiden Group One race aboard Silent Sedition in Friday night's William Reid Stakes at Moonee Valley.

Mallyon took a moment out of his celebration of his first feature win for Godolphin to send his thoughts to Williams and his family.

"(Williams's fall) is unfortunate and has slightly dampened the win a tad but there was a probably a silver lining that we got the money," Mallyon said.

"It was such a big thrill to watch Katelyn ride her first Group One winner. It was just a shame it was so late at night because I woke my own kids up screaming at the TV.

"It was nice to chime in today. I'm sure mum and dad are beside themselves and it's great to have a bit of success and share that with my sister."

Tally ($8) defeated the Mike Moroney-trained Vengeur Masque ($21) by a half-head while Tasmanian galloper Settler's Stone ($41) ran home well late to grab third ahead of the $2.10 favourite The Gold Trail.

Earlier, apprentice Beau Mertens capped the best day of his short career with his win aboard the Mick Price-trained Bassett in the Listed Hareeba Stakes (1200m).

Basstett's narrow success over Prussian Vixen and Well Sprung gave Mertens his first quartet of winners at a city grade meeting and his maiden stakes victory.

Price noted Mertens' father, Peter, rode the trainer's first Group One winner aboard Rustic Dream in the 1999 Futurity Stakes.