Tim Clark has combined with Gai Waterhouse and Adrian Bott for an early double at Rosehill.

A few extra training sessions in the barrier stalls have helped improving Tulloch Lodge gelding The Three Hundred post an overdue maiden win at Rosehill.

The horse started an odds-on favourite first-up at Hawkesbury last month but went up in the air as the gates opened, losing valuable ground before closing well to finish third.

There was no repeat of those antics in Wednesday's TAB Plate (1400m) as Tim Clark took The Three Hundred ($7.50) to the front and he found plenty in the straight to post a three-quarters of a length win over California Bay ($4) with Great White Shark ($9.50) another 3-1/2 lengths away third.

Clark expects the Gai Waterhouse and Adrian Bott-trained gelding to improve again as he is stretched out in distance.

"It was all about execution and he did that really well today," Clark said.

"Gai has done a bit of work with him between runs at the barriers and that made all the difference.

"Distance is going to be his friend. He's got a really relaxed nature and a mile to 2000, I don't think it's going to be beyond him."

Clark and the Waterhouse-Bott combination made it an early double two races later when the Lloyd Williams-owned Newfoundland posted his first Australian win in The Agency Real Estate Handicap (2400m).

The sparingly raced six-year-old is a winner over 2600m overseas and Clark says he enjoyed the bigger Rosehill circuit after filling a minor placing at Canterbury last start.

"Let's hope he doesn't go back to Canterbury ever again, he enjoyed the bigger track and obviously stepping out in distance," Clark said.

"I felt he was going to be the superior stayer and he showed that.

"He had the race won a long way from home and he is just getting better and better."

Joao Moreira made his first mark in Sydney during his latest stint with a double for Chris Waller.

Moreira opened his account aboard Seafall in the Precise Air Handicap (1800m) before taking out the final race on Pippie Beach, his victories coming less than two weeks after he snared the Group 1 Underwood Stakes at Flemington aboard the Waller-trained Buckaroo.

Moreira will be back in Melbourne on Saturday to partner the in-form horse in the Turnbull Stakes (2000m), one of six rides for the decorated hoop at the feature meeting.