Carruthers, a veteran half-brother to Cheltenham Gold Cup winner Coneygree, triumphed at Newbury for trainer Mark Bradstock and jockey Nico de Boinville.
The 12-year-old, bred by Lord Oaksey, landed the Ultima Business Solutions Silver Jubilee Handicap Chase.
Carruthers (8-1) was victorious back at the Berkshire track more than three years after his Hennessy Gold Cup win.
"The story just gets better and better," said assistant trainer Sara Bradstock, the daughter of Lord Oaksey.
Carruthers held on after a brilliant round of jumping to score by a neck from Amigo, ridden by Tom Scudamore.
Coneygree won for De Boinville and Bradstock - who has a stable of just 10 horses - at Cheltenham eight days earlier.