Tysou (10-1) turned the form around with top weight Dempsey to claim the rearranged Victor Chandler and give Bill and Tracey Brown a famous one-two.
The former owns the Nicky Henderson-trained Tysou, who outstayed the front-running Dempsey up the hill to snatch the prize from his wife's grasp and gain revenge for a defeat at this course last month.
Dempsey ran a game race under his welter burden, but after pulling hard early and then duelling with Hoo La Baloo for the lead throughout, he could not fend off the late thrust of Mick Fitzgerald on the nine-year-old, who prevailed by two lengths.
Hoo La Baloo went off the well-backed 5-2 favourite, but his jumping let him down in his first try outside novice company. Kalca Mome (25-1) ran on to get third, a further three lengths back.
Fitzgerald said: "I'm not getting carried away because they went fast in front and that played into our hands, but he really does seem to be a different horse this season."
"I have doubted him a bit in the past, but he has grown up and he gave me his everything."
Mark Pitman said of the runner-up: "He is at the top of his game at the moment and I thought we had it won."
"But if you are going lose to any horse, it might as well be the one owned by your owner's husband!"
Filed by Katie Byrne
