Muirhead benefited from a typically bold Paul Carberry steer to record an emphatic victory in the Munster National at Limerick yesterday.
Minsk, meanwhile, won the Irish Cesarewitch at the Curragh.
Minsk’s triumph, at 4-1, was trainer John Oxx’s eighth success in the race.
“I thought the handicapper might have got him after his last win, but it just shows that when they're improving you can never be sure what they're capable of,” said Oxx.
The Munster National got under way with a bruising melee that saw Glenstal Abbey crash out, taking two others with him at the first fence, reducing the field to 12.
Carberry just about navigated his way through the carnage and rode a supremely confident race thereafter on the Noel Meade-trained gelding.
A Grade One-winning novice hurdler four years ago, Muirhead, which was returned at 10/1, was contesting a handicap and three miles for the first time in the €48,000 showpiece.
When Davy Russell crept up the inside of long-time leader Casey Top on the well-supported Bideford Legend as the field turned for home, favourite backers looked poised to collect.
But Carberry eased Muirhead into a narrow lead approaching the final fence and the eight-year-old cruised home by a length and three quarters on just his fourth chasing start from Bideford Legend.
Following a Fairyhouse treble on Saturday, it was a fine end to the weekend for Carberry and Meade.
“After he got through all the fallen horses at the first, I thought his luck might be in,” Meade, who was winning the race for the second time, reflected afterwards.
“He jumped great after that, and he has very little mileage over fences. After he won the Royal Bond Novice Hurdle he ran in very good Grade Ones and it kind of took its toll on him.
“He wouldn't like real heavy ground, so it's not out of the question that he could go to England next, maybe for the Hennessy Gold Cup.”
Jamie Codd became the first amateur rider since 1988 to go through the card in a point-to-point when he rode all six winners at Tinahely in Wicklow yesterday.
Another contentious attempt to reach beyond the sport's parish boundaries gets under way today.
The new whip regulations, announced by the BHA last month, come into force today and limit a jockey on the Flat to seven strokes in a race, while over jumps it is eight.