Robert and Sam Waley-Cohen were out of luck at Catterick with Rumbavu who could only finish second in the John Wade Skip Hire Novices Hunter Chase to 50-1 chance Killary Bay.
Rumbavu, a winner of five point-to-points, was making his debut under Rules and was sent off the 11-8 favourite to give the father and son team a confidence boost ahead of Long Run's bid to regain the Cheltenham Gold Cup tomorrow week.
Having travelled keen early under Sam Waley-Cohen, the seven-year-old lost his place before staying on again to grab second.
Robert Waley-Cohen – owner and trainer of Rumbavu – is chairman at Cheltenham and was in relaxed mood ahead of the Festival, which starts on Tuesday.
"I think he needs every yard of three miles," he said.
"He was very keen early on. I was impressed with his jumping and I'm sure he'll come on a lot."
Rumbavu was sporting brown cheekpieces, which Long Run is likely to wear next week.
Waley-Cohen added: "Long Run had just got a little bit idle, as we all do, and they just help him focus and concentrate."
Long Run is currently 6-1, with Bobs Worth the 3-1 favourite.