Special Tiara shocked the Cheltenham crowd on Wednesday as he beat hot favourite Douvan to win the Betway Queen Mother Champion Chase.
Willie Mullins' stable star, Douvan, went into the race as the odds-on favourite but he never looked comfortable.
It was Special Tiara who set the pace and looked in cruise control for much of the race under jockey Noel Fehily.
He had to cling on towards the end though with Fox Norton putting in a strong finish, but the 10-year-old held on to claim the spoils, with Sir Valentino back in third, while Douvan came home in seventh.
Fehily was understandably elated with the ride, saying: "Unbelievable. He's such a great ride, he's everything a two-mile chaser should be. He's a very good horse.
"I didn't so (beat Douvan), but I thought I had a great chance of being second. I got over the last and was surprised something hadn't come to me, but I knew he wasn't stopping.
"He has one way of running and that's flat to the mat and jump - I just let him get on with it. I've always loved two-mile chasers, the Champion Chase is the one you want to win. To win it is fantastic."