On a day when Godolphin's rising star three-year-old Kementari takes on champion Winx at Rosehill, another colt from the powerful racing operation also gets his own chance to shine on the Group One stage.

Randwick Guineas winner Kementari clashes with Winx in Saturday's George Ryder Stakes before stablemate Viridine takes aim against older horses in Group One Galaxy.

Godolphin trainer James Cummings has seen enough from Viridine since his closing fourth first-up in the Challenge Stakes to be bullish about a big performance from the colt who is chasing his first Group One win in the 1100m race.

"We were all really impressed with his run, but we were even more impressed with him on Tuesday morning when he monstered the line in a track gallop," Cummings said.

"If he's as ready as we feel he is, then he's ready to run a very big race here.

"A result here would be just as exciting as seeing Kementari run in the George Ryder."

Viridine has 50kg in The Galaxy but Racing NSW stewards have permitted jockey Brenton Avdulla to ride the colt 1kg over.

Avdulla won the Listed Heritage Stakes and Group Two Roman Consul Stakes on Viridine last spring before finishing fifth on the sprinter in the Group One Coolmore Stud Stakes.

He was aboard again in the colt's return in the Challenge Stakes at Randwick.

"He ran well the other day behind Redzel and is second-up with no weight on his back," Avdulla said.

The prospect of a rain-affected track has made proven wet-track performer Jungle Edge a firmer in early betting.

Jungle Edge, who was third in the Galaxy last year on a heavy track, assumed favouritism at $4 on Wednesday.