An international raider has won the $1 million George Ryder Stakes for a second straight year, with Japan's Real Impact upstaging the locals to take the Group One.

Regarded as the outsider of the two Japanese runners, Real Impact ($11) showed he meant business from the outset when James McDonald took him to the front.

The horse dug deep when challenged in the straight by Criterion ($9.50), which looked to get his head in front before Real Impact dived again on the line to snatch back victory by a short half head.

The win was a pleasant surprise for McDonald, who hadn't ridden the horse before he was legged on at Rosehill on Saturday.

"That's the best thing. I didn't know (what to expect). I hadn't sat on him," McDonald said.

"They always said he was a very good galloper. It's a good result."

The victory gave McDonald his second Group One of the afternoon after his Ranvet Stakes win on Godolphin's Contributer.

Real Impact's trainer Noriyuki Hori made the trip to Rosehill and, speaking through an interpreter, he said the win was a thrill.

"I'm very happy to repay the great support I've had here," Hori said.

The Doncaster Mile at Randwick in two weeks has been the main race on Real Impact's radar and that plan hasn't changed, although Hori will consult the horse's owners before committing to a start.

Criterion's trainer David Hayes was disappointed not to grab his second Group One win in the space of a week after taking out the Australian Cup with Spillway.

"It's a bit frustrating not to win, but it's good heading to the Championships," Hayes said.

"We deliberately kept him on the fresh side and that might have cost him."

Three-year-old Kermadec ($5) bungled the start and was doing his best work late for third.

Chris Waller will let the dust settle, but the Doncaster is an option if Kermadec gains a start.

Stablemate Royal Descent ($31) finished fourth in a run jockey Kerrin McEvoy said showed she was on target for the Randwick mile.

Japan's other Ryder runner, the $6.50 chance World Ace, ran 11th.