Far from Kementari being knocked off his stride by his first encounter with Winx, James Cummings believes the George Ryder Stakes has set the colt up up perfectly for the Doncaster Mile.

Godolphin's head trainer says finishing 1-3/4 lengths from the champion when third at Rosehill has topped the three-year-old off for Saturday's $3 million feature at Randwick.

"We'd been impressed to see the change in the horse leading into the George Ryder and after racing so well against Winx he seems to have come out of it with more energy," Cummings said.

"It was an impressive effort to finish third, less than two lengths off the world's greatest horse."

Kementari has recovered well from the George Ryder Stakes (1500m) and returns to the scene of his first Group One win, the Randwick Guineas (1600m) on March 10.

"He's certainly looking like he's still on the rise which is perfect considering what he did at this track and distance in the Randwick Guineas," Cummings said.

Kementari was the $3.70 favourite with the TAB on Wednesday while Happy Clapper, runner-up in the George Ryder was the $5 second elect.

Cummings is optimistic Astoria will acquit himself well in the Group One Australian Derby (2400m) after being pipped by Levendi in last Saturday's Group Two Tulloch Stakes (2000m) at Rosehill.

"Astoria comes into the Derby with a really perfect grounding for a 2400 metre race," he said.

"He's been consistent throughout his preparation and for me, he hasn't run a disappointing race."

Encryption ($14) represents the stable in the ATC Sires' Produce Stakes (1400m) for two-year-olds.

"We've been happy with how he's gone ahead since winning the Black Opal in Canberra a few weeks ago," Cummings said.

"It would be fitting to see him go well in a race his mother (Guelph) won a few years ago."