The impending heatwave in Melbourne is causing little concern for Te Akau’s superstar sprinter Imperatriz as she approaches an attempt at her tenth Group One on Saturday.

Imperatriz will contest the time-honoured Gr.1 Newmarket Handicap (1200m) at Flemington, a meeting that Racing Victoria has rescheduled to commence at 10:45am local time due to the forecast predicting a 39 degree high on Saturday afternoon.

“The decision to start early has been made in the interests of horse and participant welfare, with RV’s racing in hot weather policy to be enacted,” a Racing Victoria Spokesman said.

Flemington track manager Liam O’Keeffe commented the track would start a Good 4, improving to a Good 3 later on the eight-race card, which includes five Group-level races.

“It’s better to get it done and dusted early. It will probably save us watering in the morning,” he said.

Ben Gleeson, Te Akau’s Melbourne-based assistant trainer, reported Imperatriz has enjoyed a relatively cooler week alongside stablemate and fellow Newmarket Handicap contender Skew Wiff.

“There’s no concern really,” he told Racing.com. “They've all got to deal with the heat themselves, every one of them. It's a pretty cool week, it's not like they're facing the whole week of warm weather.

"It should just be a nice-enough day by that time to be running. I don't think it will be an issue for anyone, really."

Imperatriz currently lies a $2.40 favourite on the TAB Fixed Odds for the Newmarket Handicap, while Waikato Stud mare Skew Wiff is among the lesser-backed runners at $26.