ASCOT, England (AP) — Mastercraftsman fought back to win the St. James's Palace Stakes on the opening day of Royal Ascot on Tuesday.

The 5-6 favorite looked destined for defeat as Delegator edged in front inside the final furlong but the Irish 2000 Guineas winner dug deep and stuck his head out to push back in front by a neck at the line.

Ridden by Johnny Murtagh, Mastercraftsman was one of three runners for trainer Aidan O'Brien, who was looking for a sixth success in the Group One feature race.

"It was unbelievable, a great performance. He's an amazing horse with speed, stamina, and all ground comes alike to him," O'Brien said. "It was a great performance from the horse and a marvelous performance from Johnny."

In the opening race, Paco Boy, trained by Richard Hannon and ridden by Richard Hughes, won the Group One Queen Anne Stakes.

Tuesday's races were attended by Queen Elizabeth II, who has been to every Ascot meeting since 1945. The monarch, who arrived with the royal family in their traditional carriage procession around the course, a golden yellow and white silk dress.