Faugheen won the Champion Hurdle as Irish trainer Willie Mullins made history by claiming four big races on one day at the Cheltenham Festival.
The unbeaten 4-5 favourite led home an unprecedented Mullins 1-2-3 from Arctic Fire and two-time victor Hurricane Fly.
Jockey Ruby Walsh had already won on Mullins's pair Douvan and Un De Sceaux.
But a Walsh quadruple, that could have cost bookmakers £40m, was dashed when Annie Power fell at the last, Mullins's Glens Melody edging the Mares Hurdle.
Faugheen, nicknamed 'The Machine', made it nine wins from nine after Walsh sent his mount to the front, a position he maintained throughout.
"It is some training performance to have the 1-2-3. The man's a genius," said Walsh of Mullins.
A record first-day crowd of 63,249 was reaching fever pitch with many punters backing Walsh's mounts in accumulators, before Annie Power dramatically came down when victory looked assured.
THE £40m FALL
"Annie Power's was the most expensive fall in National Hunt history," said David Williams, a spokesman for bookmakers Ladbrokes.
Punters had latched on to the 'Fab Four' of favourites, putting their faith in the combination of the Festival's all-time leading jockey and one of the most successful trainers of recent times.
Mullins said he had a text from a friend "wishing him the worst day in bookmaking" history - and it was very nearly one of them as accumulators across the UK and Ireland rested on the fourth leg.
At one stage, the share prices of major bookmaking firms were down 2%. They recovered when Annie Power fell. A £50m industry hit was downgraded to a mere £10m.
HOW THE DRAMA UNFOLDED
The 2-1 favourite Douvan got the ball rolling, greeted by a crescendo of noise which drowned out the racecourse commentator, winning by four and a half lengths from stablemate Shaneshill.
Un De Sceaux took the Arkle Chase by six lengths, prompting Faugheen's price to shorten from 5-6 to 4-5 as on-course bookmakers tried to hedge their bets by placing six-figure sums on the favourite.
|What are the odds?|
|Starting prices: Douvan 2-1, Un De Sceaux 4-6, Faugheen 4-5, Annie Power 1-2.|
|Morning prices: Douvan 2-1, Un De Sceaux 4-6, Faugheen 6-4, Annie Power 4-7. A £10 treble pays a profit of £125. A £10 four-timer would have paid £196.|
|Annie Power opened up 8-13 but was shortened to 1-2 as panic spread among betting firms.|
In warm sunshine, punters were relishing the chance to join the bandwagon - boisterous chants of "Ruby, Ruby, Ruby" going up as he delivered on three occasions.
It was so nearly a fourth, before Annie Power fell at the final hurdle, leaving a rueful Walsh to chase up the course after his mount. She was unscathed. Bookies heaved a sigh of relief. Punters wondered what might have been.
MAN BEHIND THE PLAN
The coolest man at Cheltenham as pandemonium broke out around the track was WP Mullins.
Calm, composed, polite - a gentleman you could say. But a gentleman with a fierce thirst for winners.
|Age: 58. Based: Bagenalstown, County Carlow. Stables: More than 100 horses at his Closutton yard.|
|Record breaker: Trained Hurricane Fly to a world record 22 Grade One wins.|
|Cheltenham Festival wins: 37. Third behind Nicky Henderson and Fulke Walwyn.|
|Grand National: Won with Hedgehunter (2005).|
Born into a racing dynasty, he learned at the hands of his father - Paddy Mullins, a history maker himself by training mare Dawn Run to be the only horse to win both the Champion Hurdle and Cheltenham Gold Cup in the 1980s.
Mullins, who lists Pele as his sporting hero, has seen a successful career move into fifth gear in recent years with the support of powerful backers, such as the shades-wearing American banker Ricci.
Asked what he might do for the rest of the week, the trainer joked: "Try to stay sober."
ANOTHER RUBY TUESDAY
"He has a good old clock in his head," father Ted Walsh says of his son Ruby, the Cheltenham Festival's top jockey.
Walsh is the master of timing, whether it be on the racetrack or making crucial career decisions.
|Age: 35. Born: Kill, County Kildare. Ruby is short for Rupert.|
|Leading rides: Has enjoyed big-race wins with the likes of Kauto Star, Denman, Master Minded, Big Buck's, Hurricane Fly.|
|Cheltenham Festival wins: 44. Twelve ahead of next best Barry Geraghty with AP McCoy third on 30.|
|Grand National: Won with Papillon (2000), Hedghunter (2005).|
He thrived as first jockey for leading British trainer Paul Nicholls where he enjoyed rides on steeplechasing greats Kauto Star and Denman, and outstanding hurdler Big Buck's.
But the mixture of a young family and split loyalties to Mullins prompted the Manchester United fan to split from Nicholls and concentrate on the Irish trainer's emerging stars.
SO WHAT OF AP McCOY?
Whilst Walsh has been top jockey at the meeting for seven of the last nine seasons, McCoy has to go back to 1997 and 1998 to when he last came out on top.
McCoy rated last year's Champion Hurdler Jezki as his best chance of his final Cheltenham festival, but the 2014 winner finished fourth.
However, there was a silver lining for the Northern Irishman with the victory of the JP McManus-owned Cause Of Causes in the four-mile amateur riders race.
Trainer Gordon Elliott - who won the Grand National in 2007 with Silver Birch - indicated the horse will be aimed at next month's Aintree race. McCoy is McManus's retained rider, creating another option for a fairy-tale farewell.
ANY OTHER BUSINESS
There was double joy for Walsh's understudy Paul Townend, who profited on 6-1 second favourite Glens Melody when Annie Power fell.
He also landed the concluding novices' chase race on 11-1 chance Irish Cavalier for Welsh trainer Rebecca Curtis.
Grand National contender Druids Nephew, ridden by Barry Geraghty, gave trainer Neil Mulholland his first Festival win in the handicap chase.
But there was also sadness, following confirmation that Theatre Queen was put down following a heavy fall in the penultimate race.
WEDNESDAY'S MAIN ATTRACTION
Last year's winner Sire De Grugy and 2013 victor Sprinter Sacre face off in the Queen Mother Champion Chase at the Cheltenham Festival on Wednesday.
Both horses are having their second runs after returning from setbacks.
Sprinter Sacre was the best chaser of his generation before a heart scare ruled him out for more than a year.
Their rivals in the speed test over two miles include Champagne Fever, Mr Mole and Dodging Bullets.
Walsh rides the grey Champagne Fever for Mullins, while his friend and rival McCoy is on the Nicholls-trained Mr Mole.
Dodging Bullets, bred by leading Flat jockey Frankie Dettori, will be ridden by Sam Twiston-Davies for Nicholls.
Wednesday also sees the RSA Chase where Mulholland and Geraghty team up with The Young Master, while Mullins saddles seven of the 24 runners in the Champion Bumper.