The final day of February could deliver a first in the career of John O'Shea.

The Godolphin trainer will have four Group One runners across three races on Saturday as he bids to win his inaugural major for Sheikh Mohammed.

"For all the midweek wins and Saturday wins, this is ultimately what we're in the game for," O'Shea said.

Bookmakers fancy his chances, installing Godolphin's Contributer favourite for the Group One Chipping Norton Stakes in Sydney.

Stablemate Earthquake also sits at the top of markets for the Oakleigh Plate at Caulfield although that race is less clear-cut with 12 of the 18 runners at $18 and under.

Sampeah ($11) is regarded as the trainer's best chance in the $1 million Blue Diamond Stakes in which he also runs city winner Bantam.

Godolphin's juveniles have been the backbone of their success this season with 13 individual youngsters winning 14 races.

Sampeah did his part for the team with a Rosehill victory in November before returning with an eye-catching third to Of The Brave in the Blue Diamond Prelude for colts and geldings.

"I think he's got a good profile for a Blue Diamond," O'Shea said.