Passato defied the steadier of 11st 12lb in admirable fashion to supplement a recent Flat success in the Birmingham Post Handicap Chase at Stratford.
Surrendering between 12lb and 26lb to his four rivals, the Jo Davis-trained eight-year-old would not be denied as he gave his all for Paddy Brennan to ward off Dean's Grange by a length.
"He's an absolute star. To win like that with all that weight is just brilliant," said Hungerford-based Davis of the 9-4 favourite.
"I knew he was really well and he's as strong as I've had him, but with the way the ground was I wasn't going to run him as he had to carry such a big weight.
"Paddy texted me on Friday morning and said we should run and that the ground would dry up.
"He has won nine races for me now on the Flat, over hurdles and fences.
"I don't know where we'll go next. The handicapper will have his say and I don't want to run him for him to get beat as he tries so hard."
Tzora came with a rattling late run down the centre of the course to snatch the Sunday Mercury Handicap Hurdle.
Having his first start since joining Devon trainer Martin Hill, the 33-1 outsider outstayed the gambled-on Smalib Monterg to win by a length and three-quarters under Hadden Frost.
Hill said: "He was a bit of a decent act about two years ago. We seemed to have rekindled him a bit and he's back doing the right job, which is two-mile hurdling.
"We're very pleased for a horse that cost 2,200 guineas from Ascot sales three months ago.
"He as a bargain buy. He's obviously had leg trouble. He's run in a point-to-point and a hunter chase without any ill effects, so we thought he was worth taking a chance with.
"He'll stick to the same job now through to the autumn, then we might think of putting over fences as he jumps them fine."