Danny Riordan’s runner, racing from trap one, saved his best start of the competition for the £250,000 decider and followed the Irish hotpot through the opening two turns.
The crowd cheering for the jolly were suddenly silenced when Rio Quattro flew past him down the far side to go clear from the third turn.
Tynwald Bish moved into second at this point but had no answer to Rio Quattro, who went on to score by a length and a quarter in 28.24sec.
Track record breaker Eden The Kid, who had dropped out of the boxes, came from nowhere to get third a further short head behind.
The favourite Farloe Blitz faded from the last turn to finish fourth, a length further back. Making Paper was fifth with Millwards Davy bringing up the rear.
Riordan, who suffered a stroke in Australia 18 months ago, was delighted with the victory. He said: “I’ve been trying to win this for over 40 years.
“We’ve had semi-finalists with Droopys Corelone and Rio Riccardo but Rio Quattro is our first finalist and it a dream come true to see him cross the line in front.
“I bought him from Michael and Sean Dunphy after he caught my eye trialling at Kilkenny.
“We wanted to run him in last year’s Derby but he wasn’t right and came back to win the Puppy Race on finals night in a fast time.
“Six months ago we decided to lay him out for the Derby thinking he was good enough. We had great faith in him and he’s done it for us.
“When he turned second so close to the favourite I thought he would win and he was brilliant.
“I’ve got a great team at home to thank for this victory.”
For the favourite Farloe Blitz it was fourth time unlucky in a major final. He was beaten odds-on favourite in the Texacloth Puppy Trophy, the Irish Puppy Derby and the Supersprint at Cork and there were no excuses here.
The wait for a first Irish winner since Loyal Honcho in 2008 goes on.
Ted Last (8-13) overcame all sorts of traffic problems to land the William Hill Puppy Stakes over 480 metres.
Last into his stride and occupying the same position at halfway, Charlie Lister’s runner came from nowhere to catch My Mate Max, who had taken up the running from pace-maker My Little Dream at the third turn, and score by a short head in 28.71sec.
Ian Sutherland, assistant trainer to Charlie Lister, said afterwards: “He’s a never say die dog that doesn’t know when he’s beaten. He’s a young dog that may stay six bends in time but we’re in no rush to step him up.”
Liz McNair had a 1-2 in the William Hill Sprint when her Ballybee Brewery (7-2) gave a start and a short head beating to Skate On in 15.84sec.
Swift Keith (9-2) was an impressive winner of the William Hill Download The App Puppy Stakes over 480 metres.
John Mullins’ runner flew out and made the bend clear of Juvenile winner Ballymac Brogan and went on to beat that rival by just over two lengths in 28.16sec.
Mullins said: “He’s a great dog and loves it here at Wimbledon. It’s great to win on Derby night and will go over the Dundalk for the International on July 12.”
Millwards Teddy (8-15) was a record breaking winner of the William Hill Home of Betting Stayers Stakes over 687 metres.
Dean Childs’ runner overtook Kakantu with a lap to go and came home seven lengths clear of Teejayspowerhawk by seven lengths in 41.13sec, taking five spots off Racenight Jenny’s previous best.
Carly Philpott assistant trainer said: “We were worried about the draw but he did everything right.
Mitch Millward, part owner said: “He’s running better than ever and has completed a four-timer in track record fashion.”
Forest Twilight was another easy winner of the William Hill Exclusive Mobile Offers Ladies Stakes over 480 metres.
Hayley Keightley’s runner, a 5-2 chance, flew out and went round the bend in front of Fridays Angel. The favourite Evanta Evita moved into second at halfway but had no answer to the winner who scored by almost four lengths in 28.35sec.
Keightley said afterwards: “She ran awesome and I’m over the moon with her.”
Keightley had a quick double with Roxholme Magic in the William Hill Dorando Marathon over 894 metres.
Droopys Cottage went clear and looked like being swallowed up at the penultimate turn. However the chasing pack bunched up and she kicked on again but Roxholme Magic, a 9-4 chance, came with a grandstand finish to get up and score by a length and a half in 55.65sec.
Mark Keightley, Hayley’s husband said afterwards: “You’re on you edge of your seat watching this bitch as she definitely has her own ideas about the game but when she can get across to the outside she is brilliant.”
Jetstream Reason landed the William Hill Champion Hurdle over 480 metres.
Steve Gammon’s runner led to halfway where he was joined by the favourite Razldazlnewstalk and Alittlelesslip. They came together at the third turn which allowed Jetstream Reason to go clear again and beat Alittlelesslip by a length and a half in 29.24sec.
Gammon said afterwards: “He’s been off with lots of little problems and the run in the heats would have brought him on a lot.
“He toughed it out on the rail to win.”
Domino Storm was an impressive winner of the William hill Derby Plate over 480 metres.
Mark Wallis’s bitch was led to the second turn by Old Joe Golden but she nipped inside and came home almost four lengths clear of My Real Muttley in 28.23sec.
