Somersby has won the Victor Chandler Chase at Ascot after travelling superbly under rider Dominic Elsworth.
Last year's runner-up improved under new headgear to defeat favourite Finian's Rainbow to win at a price of 9-2.
The win gave Henrietta Knight her first grade one success in seven years and Best Mate's trainer looked delighted with the result.
Elsworth said: "I'm delighted for the horse. He's been a bit of a bridesmaid, but he's done it nicely. I always knew he was going to stay on towards the end."
Somersby's odds for the Queen Mother Champion Chase have been slashed after the victory, despite Knight claiming their first priority may be the Ryanair Chase.