Despite making a mistake at the last flight, the Grand National winner quickened easily on the flat to get up to beat Destin D'Estruval by half a length.
His rider, Mick Fitzgerald, said: "If he hadn't made a mistake at the last, he'd have won without coming off the bridle.
The winning trainer, Terry Casey, added: "That was a nice run round for him and should have put him right for the King George. We'll school him over fences on Sunday morning."
William Hill and Ladbrokes have cut Rough Quest a point to 5-1 joint- second favourite for the Kempton race.
Warren Marston will be replaced by Norman Williamson aboard Nahthen Lad when the Jenny Pitman-trained Sun Alliance Chase winner makes his reappearance at Bangor today and Williamson will remain in the saddle when the gelding lines up for the King George. Marston, Pitman's stable jockey, rode Nahthen Lad in all six starts last term which included three other wins.
Trying Again has been well supported, from 16-1 to 12-1 with Ladbrokes, for Kempton, but his trainer, David Gandolfo, is keeping his options open. The horse is yet to race on fast ground.
"The Mid Season Chase at Wincanton is a possibility and I'll put him in a three-mile chase in Ireland as well," Gandolfo said.Reuse content