Jockey Christian Reith has benefited from a second show of leniency from stewards within a week as he landed a Canterbury Classic upset on Le Cordon Bleu.

Stewards allowed Reith to ride the $19 chance 1kg overweight after the introduction of new handicapping rules and subsequent confusion left a shortage of jockeys who could make the new 53kg minimum.

Reith made the most of his opportunity as Le Cordon Bleu appreciated a high-pressure Listed sprint to strike late and beat the $101 outsider Wouldn't It Be Nice at Canterbury on Saturday.

Grunderzeit ($10) took third - and run of the race honours after being posted on a limb - a half length away.

Reith angled for a run he admitted was too sharp to take as he navigated for room at the 200m.

Le Cordon Bleu came out of the pocket with the Wayne Kerford-ridden Sirbible directly to his outside and Blake Shinn's mount Flippant deeper on the track.

It was this manoeuvre that ensured Reith was given a stern warning.

"How (Kerford) doesn't clip heels and how he doesn't take hold of his mount to avoid the heels of Blake Shinn's mount there, I don't know," chief steward Marc Van Gestel told the jockey.

"You've got to exercise more care.

"If you clip heels and (Kerford) comes down it's then not exercise more care, but a month on the sidelines.

Le Cordon Bleu had won four of his 15 starts going into Saturday but he was offside with punters who had backed him into clear-cut favouritism at Rosehill last month only to finish down the track.

He was found to be suffering an elevated heart rate and was ordered to barrier trial, but co-trainer Michael Hawkes said he wasn't sure the veterinarian's diagnosis had anything to do with the poor showing.

"I had no reason for it. They said he had an issue," he told stewards.

"(Deputy chief steward) Mr Dingwall rang me after that race and I was disappointed. You know what, he didn't attack the line that day.

"But he's been good since, his work's been good ... good as gold.

"And he likes this track and he dropped a lot in weight today."

Hawkes said Le Cordon Bleu had earned the right to be a part of the stable's team for Magic Millions day at the Gold Coast on January 14.

Le Cordon Bleu will contest the Magic Millions Sprint over 1200m and stablemate Snoopy has the Magic Millions Cup over 1400m in his sights.

Both races are carry a $1 million purse.