Bobs Worth provided Nicky Henderson with a second Betfred Cheltenham Gold Cup in three years under Barry Geraghty.
In maintaining his unbeaten record at the track, Bobs Worth, the 11-4 favourite, outstayed Tony McCoy and Sir Des Champs up the Cheltenham hill.
Long Run, Henderson's winner from 2011, attempted to make all for his amateur jockey Sam Waley-Cohen but faded into third.
Silviniaco Conti was a faller at the third-last when still going well in the hands of Ruby Walsh.