Something Wells led home Ping Pong Sivola to give trainer Venetia Williams a 1-2 in the Freddie Williams Festival Plate at Cheltenham.
The latter made most of the running in the two-mile-five-furlong contest and looked to have stolen a march on most of her rivals as she careered down the hill.
However, Will Biddick was alive to the move of his stablemate and ensured Something Wells (33-1) came out on top after a rare tussle on the run-in.
Leading Irish fancy Clarified parted company with Paul Townend in the early stages, while Finger Onthe Pulse travelled well before weakening turning for home.
The first two ultimately pulled well clear, with Something Wells emerging a three-quarters-of-a-length winner.
Notable D'Estruval (8-1) shaped with plenty of promise in third, but was another 18 lengths adrift at the line, while Three Mirrors (9-1) came from a mile back to claim fourth.
A delighted Williams reflected: "The first two and not a hairsbreadth between the pair of them.
"We had hoped to get Ping Pong in the Jewson, but she didn't make the cut.
"I'm so pleased for the owners Favourites Racing. They are such an enthusiastic gang.
"If Something Wells had some sort of a chance at the top of the hill I knew there would be some noise behind me - they didn't disappoint me."
Biddick said: "He fell here last year and it's just nice to have my first Festival winner for Venetia.
"I thought I would have more turn of foot than Ping Pong Sivola.
"They went a real good gallop and they didn't stop either. Ping Pong forced the gallop again.
"He gave me such a good ride - unbelievable."
Arthur Moore said of third-placed Notable D'Estruval: "He had every chance and Venetia has done very well with her two.
"He might go for the Irish National or perhaps the Topham at Aintree."