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.