The two-mile chasing crown had alluded trainer Willie Mullins for 34 years - now the Irish maestro has two in 12 months, taking his Festival tally to a record-extending 92 winners.
Mullins' fourth winner of the week put up a swashbuckling display, the 6-5 favourite slaying the compact but classy field of seven to land one intrepid punter a mammoth £400,000 wager placed with a bookmaker in Brighton.
Ridden spotlessly by Paul Townend, Energumene shared the lead with Editeur du Gite, before clicking into top gear round the home turn.
Pinging the last two fences he raced up the hill in front of stands packed with tens of thousands of racegoers including Britain's Camilla, Queen Consort, to land the spoils named after her husband King Charles III's late grandmother, one of National Hunt racing's most committed supporters.
Rachael Blackmore got a great ride out of Captain Guinness (12-1) to take second, albeit a respectable 10 lengths behind, with Greaneteen at 25-1 a further 24 lengths adrift in third in what turned into a procession.
What made the victory taste even better for Energumene's connections was the sense of a champion reestablishing himself after the nine-year-old had fluffed his lines in his prep for Wednesday's showpiece at the Cotswolds track in January.
That day he had Editeur du Gite and Edwardstone in front of him, but they could only muster fourth and fifth as Energumene joined Altior and Master Minded as the only back-to-back winners of the Champion Chase this century.
"Today he was just spot on," Mullins told ITV television.
"Paul came home from the Clarence House (his prep race) and said 'they won’t beat us again'," he added.
"I was hoping to win but the way he did it was something else."
"You don't win championship races like that normally. It's a pleasure to ride and do anything with him," added Townend.
Mullins' Midas touch, already in evidence when he saddled the first three home in the opening novices' hurdle, was on target to strike again with well-backed favourite Dinoblue in the Grand Annual Challenge Cup.
But a sketchy jump at the last left the way clear for Maskada, a mare winning appropriately on Ladies Day at the Festival.
Trained by Henry de Bromhead, the 22-1 shot was a ninth win out of 14 for Ireland in their annual rivalry with their British counterparts.
One popular 'home' winner came when Lander Dan took the 26-runner Coral Cup Handicap for trainer Dan Skelton and his jockey brother Harry, sons of Nick Skelton, the British showjumper who won gold at the Rio Olympics in 2016 at the ripe old age of 59.
