Ibis Du Rheu battled on bravely to outpoint Flying Angel in a close finish to the Martin Pipe Conditional Jockeys' Handicap Hurdle at Cheltenham.
It was a second Festival win of the week for trainer Paul Nicholls and a first ever for Jack Sherwood.
He kept his cool in a typically difficult 24-runner race to bring Ibis Du Rheu (14-1) through to challenge Flying Angel in the extended run from what became the final flight.
It was only in the last 100 yards that Ibis Du Rheu got the measure of last weekend's Imperial Cup winner to get the verdict by a length and a quarter.
Sky Khan was a length and a quarter away in third with Tully East fourth.
What would have been the last obstacle was omitted as Jeremiah McGrath was being treated following a fall from Laurium on the first circuit.
Nicholls said: "He's a funny horse, he's always had plenty of ability, they missed out the last and he stayed on.
"It's brilliant for Jack, it's great to give him a Festival winner, and the Hales' (owners).
"It's a funny old game because at home Qualando (stablemate) would pick him up and carry him but there we are.
"It's nice to have a winner on the same day as Harry (Fry) and Dan (Skelton), my two former assistants, a great day."