A stunning year for Damian Lane has continued with the Australian jockey adding his first Cox Plate on star Japanese mare Lys Gracieux.

Having already won the Golden Slipper on Australian filly Kiamichi in March and last week's Caulfield Cup on Japanese horse Mer De Glace, Lane added the next jewel of Australian racing on Saturday, with Lys Gracieux in the $5 million Cox Plate (2040m).

Widely tipped to prove superior at The Valley in the weight-for-age race, the Yoshito Yahagi-trained mare started $2.50 favourite and came from back in the field to overhaul three-year-old Castelvecchio in the straight.

Lys Gracieux beat Castelvecchio ($8.50) by a widening 1-1/2-lengths with New Zealand gelding Te Akau Shark ($17) finishing strongly along the rail for third, another two lengths away.

"She's a genuine superstar," Lane said of the first Japanese-trained winner of the Cox Plate.

"The weight of expectation during the week was getting a bit much and it was just great for her to come through and prove what she can do.

"The speed was solid going to the first corner. I didn't want to get into a battle that would empty her. I took my medicine and rode her cold and she just let go with a great turn of foot.

"I've said a few times this week she's one of the best, if not the best horse I've sat on and I've ridden some good ones here over the last few years.

"So I was confident she was the right horse."

Lane won the Group One Takarazuka Kinen on Lys Gracieux during his successful two-month stint in Japan earlier this year and that trip has led to his wins in the Caulfield Cup and Cox Plate.

He has the ride on Mer De Glace in the Melbourne Cup, bidding to become the first jockey to win Melbourne's three biggest spring races in the same year.

"It's been a massive year and the opportunities have just been amazing," Lane said.

"I'm just so happy that I've been able to capitalise on them.

"To grow up as a racing fan watching this race and watching my idols win this race, to now be on the honour roll is such a privilege."

Along with the $3 million first prize money, Lys Gracieux also claimed a $2 million bonus for winning the Takarazuka Kinen as part of a Cox Plate bonus.

Having been in Australia and watched Kingston Town win one of his three Cox Plates in the early 80s, Lys Gracieux's trainer fulfilled one of his own ambitions to bring a horse to the race and win.

He rated the Cox Plate victory the best of his career.

"For me personally, this is the best," Yahagi said through an interpreter.

"I was confident because she's been thriving since she's arrived in Australia.

"She's been better than what she was in Japan."

Young Sydney trainer Richard Litt was proud of Castelvecchio who showed he warranted his place in the field with a gallant showing under Craig Williams.

"It was only his ninth start today so we've got a lot to look forward to," Litt said.