Johnny Murtagh's 16-1 mount hung on the tail of Persian Punch for the majority of the race, but came through to hit the front with half a mile remaining.

But, as Persian Punch faded, Vinnie Roe and Wareed appeared to have the legs on the mount trained by Scot Mark Johnston.

Yet Murtagh rallied the horse and Royal Rebel came back again to hand the trainer his third Gold Cup.

"He has the heart of a lion," said an exhausted Murtagh after the race.

"Once he got a chance to rally back (at Vinnie Roe and Wareed), he gave 110%"

Many felt the chance of a victory for Johnston had gone when his much-fancied Akbar withdrew from the race, with doubts remaining over Royal Rebel's temperament.

But the horse responded to the surroundings of Ascot and galloped to a memorable win - adding his name to a distinguished list of two-time winners of the Gold Cup.

"From the minute he jumped off and went past the stands in second with a circuit to go I knew we had a chance and I think he has possibly run the best race of his life," said trainer Johnston.

Royal Rebel also became the first horse to win the Gold Cup two years running since Drum Taps in 1992 and 1993.

Owner Peter Savill, who is the chairman of the British Horseracing Board, admitted that Royal Rebel had been erratic since last year's victory.

"I was not at all optimistic. He has a good day about one day in seven."

The victory was a bitter-sweet affair for Murtagh, who will miss the Budweiser Irish Derby a week on Sunday after picking up a four-day ban for using his whip with excessive frequency.

The Irishman missed last year's Curragh Classic after receiving a one-day suspension for a similar offence on the same horse 12 months earlier.

Frankie Dettori, the rider of Wareed, received an identical punishment for the same offence and will miss the same meeting.