It's A Dundeel might be an easing favourite for the Victoria Derby following his first defeat but David Payne, trainer of rival Honorius, says he will still be tough to beat.

Super Cool put himself in the picture for Saturday's 2500m Classic at Flemington when he gave New Zealander It's A Dundeel a beating in the Vase at Moonee Valley.

Honorius has twice been placed behind It's A Dundeel in Sydney including when third in the Spring Champion Stakes.

He was promoted from third to second behind Hvasston in the Norman Robinson Stakes when Corey Brown protested against Electric Fusion's rider Nicholas Hall over interference in the run to the post.

It's A Dundeel has eased from $1.90 to $2.80 to win the Derby with Honorius and Hvasston on the third line of betting at $6 behind Geelong Classic winner Solemn and Super Cool at $6.

"I don't think It's A Dundeel lost much from a Derby point of view," Payne said.

"I don't think the Moonee Valley track suited him.

"I'm sure he will be much better on the bigger track at Flemington but I also think it will suit my horse as well."

While many consider the 2500 metres too arduous on young three-year-olds, Payne believes Honorius has the grounding and the pedigree to cope with the distance.

The colt by Holy Roman Emperor from unraced mare Zarinia is a half-brother to South African champion Igugu and is from the family that produced French champion Zarkava who counts the Prix de l'Arc de Triomphe as her greatest win.

Kia Ora Stud, which bred Igugu, retained a share in her younger brother.

Honorius has won two of his 11 starts and been placed on four other occasions.

Both his wins came as a late two-year-old and were over 1550 and 1800 metres as part of a Racing NSW initiative to give juveniles experience over longer distances.

Fiveandahalfstar finished behind Honorius in both those races but his 1800m win at Rosehill on Saturday convinced trainer Anthony Cummings he was worthy of taking his place in the Derby field.