McDonald wins again aboard star mare, breaks Cup Week record.

James Mcdonald put an exclamation mark on the most successful Melbourne Cup Carnival by a jockey when he teamed with his new favourite mare Via Sistina to take out Saturday's $3 million Champions Stakes at Flemington.

The superstar Sydney-based New Zealander completed his second Group 1 double of the week when the eight-length Cox Plate heroine powered to a 2-3/4-length win in the 2000-metre event.

The win followed Champions Sprint victory on Sunshine In Paris earlier in the day, with McDonald having won both the Coolmore Stud Stakes and Empire Rose Stakes on Derby Day, to take him to 10 winners for the week.

That tally equalled the mark he set in 2021, the year he won the Melbourne Cup aboard Verry Elleegant.

McDonald broke the record in the following event, the last race of the carnival, which he won aboard the James Cummings-trained Pisanello, giving him four winners for the day.

The 32-year-old expressed his gratitude to owners and trainers for the opportunities he gets on the biggest stage in Australian racing.

"I ride for some brilliant trainers, I get on the best horses and I'm lucky to be able to drive them, basically.

"I steer them around a white rail and hope for the best and they do the rest."

While not as decisive as the Cox Plate success, McDonald knew a long way from home he would be taking his career Group 1 tally to 104 aboard the Chris Waller-trained mare.

After jumping away with the field, McDonald allowed Via Sistina to settle just worse than midfield one off the fence before creeping into the race from the 600m.

The imported seven-year-old daughter of Fastnet Rock was still under a hold when she hit the front just before the 300m, after which the $1.60 favourite surged away for a comfortable win over stablemate and defending champion Atishu ($8).

Without A Fight ($13) turned in an encouraging return at his first start since last year's Melbourne Cup, finishing two lengths astern Atishu in third spot.

"She was never in doubt, the nice building pace suited her, she just keeps going to a new level," McDonald said.

"She was very good and today was an absolute joy and pleasure and I had so much fun on her. Her performance speaks for itself."

It was Waller's second-straight win in the Champions Stakes and he continues to be amazed at what Via Sistina is capable of.

"To get the opportunity to train a horse with European form lines like she had was pretty special," Waller said.

"She did it first-up in a Ranvet and announced herself, and she's just done it consistently since.

"Over 1400 (in the Winx Stakes) and then coming out and winning a Turnbull and Cox Plates and then the McKinnon (Champions) Stakes.

"She's a pretty special horse, so I'm appreciative for getting her to train."

The $1.8m winner's cheque took Via Sistina's career earnings beyond $8.5m with the Yulong-owned charge now a raging favourite for this season's Australian Champion Horse Of The Year award with four Group 1s already in the bank for the season.