Just when the Champion Hurdle picture was looking bafflingly opaque, one breathtaking performance cast it in a piercingly clear light. Sizing Europe is the new favourite for Cheltenham's hurdling crown, and as short as 9-4 with Coral, after routing five accomplished rivals in the Irish equivalent yesterday.

An inexperienced six-year-old, Sizing Europe won the AIG Europe Champion Hurdle by eight lengths under Andrew McNamara. Hardy Eustace and Al Eile, two solid yardsticks who went off joint-favourites, were second and third and Conor O'Dwyer, who rode the former, said: “I've never been so fast. That was an unbelievable performance.”

The race must be put in sober context. There was no British challenge and neither Sublimity nor Harchibald was risked on the slow ground. The trainers of both, however, may be grateful they stayed away, because this was a revelation.

Asked if this was the performance of a new champion hurdler, an elated McNamara said: “Well, Hardy won two of them and we stuffed him, so it must have been.” Around the Leopardstown paddock, the excitement was tangible and bookmakers Cashmans, exploiting the partisan mood, offered 4-6 a fifth successive Irish-trained winner of the Champion.

Despite drifting in the betting, and running so freely it seemed he might not stay the trip, Sizing Europe bounded clear on the turn for home, jumped the last two flights exuberantly and won with insulting ease. His closest challengers have respectively won two Champion Hurdles and two Aintree Hurdles but they were left labouring.

He had not run for 70 days, missing an engagement at Christmas after a poor scope. That last run, however, had seen him defeat the subsequent Boylesports Hurdle winner, Osana, in a Cheltenham handicap. Had the weather that day not been so foul, and the visibility so dreadful, more might have registered the significance.

Yesterday was contrastingly crisp and sunny as Sizing Europe brought unfamiliar representatives to the usual cast of Cheltenham aspirants. Henry de Bromhead is into his ninth year as a trainer but his string remains modest in number. Much his biggest owner is Alan Potts, brought up in the south Yorkshire mining village of Great Houghton before making his fortune in the mineral business.

Potts was perspiringly loquacious afterwards, revelling in the first serious proceeds of a mighty outlay. On a single day, three years ago, he bought 15 store horses - among them Sizing Europe - and sent them all to be trained by de Bromhead, a man he insists is “going right to the top”. On this evidence, he may be right.

Sitting wide behind the usual, earnest pace set by Hardy Eustace, Sizing Europe held his position as Aitmatov and Ebaziyan dropped away disappointingly. Lounaos, beaten favourite in the Triumph Hurdle a year ago, could never get competitive and the field was left to the three market leaders. Soon, though, it was a one-horse race.

Afterwards, de Bromhead had the look of a man trying to cling on to perspective in the face of something extraordinary. “I'm speechless, really,” he said. “To beat those sort of horses the way he did was unreal. I was worried he was too free early on and the Champion will suit him better - the faster they go, the better he'll travel.”

There will be no further sight of Sizing Europe before March 11 but considerable interest will surround Osana's intended run in the Kingwell Hurdle at Wincanton on February 16. Osana, trained by David Pipe, was conceding 6lb when beaten four lengths by Sizing Europe and it may come down to which horse has progressed most.

Cheltenham clues were scarce on the support card. Thyne Again, winner of the Irish Arkle, is likelier to contest home targets than run at the Festival but Pomme Tiepy could now represent Willie Mullins in the Royal & SunAlliance Chase, after the injury to his intended runner, Glencove Marina.