Tony McCoy, who secured his second Gold Cup victory after Mr Mulligan took the title in 1997, said: "He's an amazing horse and it was an amazing performance. I'm so pleased to win it for JP as he's been so good to me.
"Jonjo has done an incredible job. I've got a Grand National and a Gold Cup out of the man and I love him to bits."
More top news
Man City remain five points behind Chelsea in the Premier League title race after a 1-1 draw at Stamford Bridge
Five NHS trusts in the Midlands have come under fire after it emerged bosses were sitting on more than £134 million of spare cash.
A factory worker's faithful friends saved his life by lying with him to keep him warm when he fell into a diabetic coma in the freezing cold