A dominant victory in the Group 1 Irish St Leger (2816m) has propelled Al Riffa to the top of Melbourne Cup betting markets, where he is now rated a $6 chance for the $10 million feature on November 4.

Trained by Joseph O’Brien and recently acquired by Australian Bloodstock, the high-class stayer powered away to score by four lengths at the Curragh in his first outing since the purchase. It was a statement win that left connections optimistic about his prospects in Australia.

“He’s a multiple Group 1 winner, so he’s going to carry a lot more weight, but he’s going to carry it because he’s a very high-class horse,” O’Brien said. “Whether he can win carrying the weight, we’ll find out, but he is a classy horse and he does have some of the right attributes that we think you need for the race. We’re excited to hopefully get a smooth passage down there.”

The Irishman, who has already trained Melbourne Cup winners Rekindling and Twilight Payment, will discover Al Riffa’s official impost when Racing Victoria’s David Hegan releases the weights on Tuesday.

The St Leger was Al Riffa’s third Group 1 win, adding to the National Stakes (1408m) at two and last season’s Grosser Preis von Berlin (2414m). His lead-in form was strong, with victory in the Curragh Cup and a second to Rebel’s Romance in the Hardwicke Stakes.

Dylan Browne-McMonagle has been in the saddle throughout and continues to showcase his talents abroad, though his mount on the day wasn’t limited to Al Riffa. He also rode Asfoora, but the Australian mare could only finish seventh in the Flying Five Stakes after her earlier Nunthorpe Stakes triumph at York.