Robbie Griffiths can now call himself a Group One-winning trainer after The Quarterback stormed home to win the Newmarket Handicap.

Giving Griffiths his biggest moment in almost 25 years as a trainer, The Quarterback tracked favourite Chautauqua back in the field until making his winning run along the outside fence in Saturday's $1.25 million sprint at Flemington.

The Quarterback ($21) denied Black Heart Bart by a head while Chautauqua's hoodoo in 1200m Group Ones at Flemington continued with the gelding having to settle for third, three-quarters of a length away.

Griffiths wiped away tears as he embraced connections of The Quarterback and then spoke about his first Group One success.

"To win a Group One anywhere would have been an absolute dream come true. But to do it at headquarters in the best sprint race in Australia is just amazing," Griffiths said.

He said the final seconds of the race "seemed like 45 minutes".

"It's been a long time coming," he said.

"We've been a top-ten stable for so long and haven't had the luck on the big days."

Griffiths had set The Quarterback for the Newmarket, believing it was his best chance of winning a big sprint in Melbourne.

And the trainer admitted to some confidence pre-race.

"When I legged Craig (Newitt) on I said 'I reckon he can do it'," Griffiths said.

"The instructions were simple: follow the grey horse and if you get past him you'll win.

"And Craig rode him perfectly."

It was a third Newmarket Handicap win for Newitt after victories on Miss Andretti and Shamexpress, but he took great satisfaction in playing a role in Griffith's biggest win.

"If anyone deserves it it's him," Newitt said after embracing Griffiths with a hug.

Damian Lane said Black Heart Bart turned in a massive run in his first start for trainer Darren Weir while Dwayne Dunn thought Chautauqua was going to win 200m out.

"Weight is a good leveller," Dunn said.