Another early morning trip to Caulfield may be the catalyst for Hartnell's return to Group One winning form.

Hartnell dominates betting on Sunday's Underwood Stakes (1800m) where he is pitted against eight opponents.

The James Cummings-trained gelding went to Caulfield on Tuesday from his Flemington base for another look at the course.

The Godolphin-owned Hartnell had a gallop at the track before his first-up win in the Group Two P B Lawrence Stakes (1400m) last month.

While recording a 2-1/4 length victory, Hartnell didn't race on his correct lead leg during the race but tracked around the course on his right leg during his midweek trackwork session.

Cummings says Hartnell has trained on well from his second to Humidor in the Group One Makybe Diva Stakes at Flemington on September 16.

"I was delighted to see him pull up quite well from what was a tough run," Cummings said.

"He had to burn the candle at both ends and he was able to hold off the challenges and battle on bravely for second.

"He steps out to the 1800 metres in the Underwood and he'll be well suited.

"We'd love to ride him with a little bit of cover this time, a little more neutrally from the barriers."

Hartnell, a Group Three winner in Europe, has won two Group One races since being imported to Australia, the 2015 BMW and the Turnbull Stakes 12 months ago.

Cummings says from what he has seen since taking over as Godolphin's Australian trainer, is that the gelding is ready to win again at the highest level.

"I think he's really ready to attack the line and he showed real sharpness in a gallop at Caulfield on Tuesday morning and the reports from the team in Melbourne are really strong," Cummings said.

"He's in great form. He's well within himself, ticking over beautifully and doing everything we need him to do.

"Hopefully on Sunday he can pick up a Group One for us."

Hartnell has been the odds-on favourite for Sunday's race since barriers were drawn on Wednesday.

Support has come for last year's winner Black Heart Bart and first-up Dato Tan Chin Nam Stakes winner Bonneval, who have both firmed from $5.50 to $4.60, while Hartnell remains in the red at $1.95.