Lloyd Williams has paid Chris Waller the ultimate compliment following Winx's record-equalling third Cox Plate win.

Ridden by Hugh Bowman, Winx staved off a late challenge from Humidor to win the Cox Plate in record time at Moonee Valley on Saturday.

"Leave alone the fact that Hughie handles the big occasion so well, what Chris Waller has done with that horse I think is amazing," Williams said.

"I think in my long lifetime that would go down as the best training performance I have seen in light years.

"She's a great horse and I have to ask could anyone else possibly have done that with her."

The five-time Melbourne Cup winning owner says to train a middle distance horse to win 22 consecutive races, and three Cox Plates, is unbelievable.

He said Winx had not done a lot in her career before winning the Queensland Oaks.

That victory came after she won the Sunshine Coast Guineas to begin her winning streak.

"To train a sprinter is not that difficult. They might break down or do other sorts of things, but you don't have to work them hard," Williams said.

"What Chris has had to do is gallop her over seven furlongs, a mile, get her fit for tough races.

"Yesterday was a tough race and she ran a course record.

"It's an amazing performance and the way he conducts himself, he should be Prime Minister."