(CNN) Shane Breen, an Irishman who took up show jumping to get out of going to school, produced a big surprise with a first win in the Monaco leg of the Longines Global Champions Tour (LGCT).
Breen and his horse, ten-year-old Belgian-bred stallion Ipswich van de Wolfsakker, beat last year's winner, Alberto Zorzi of Italy and Fair Light van T Heike by 0.16 seconds to clinch his first win in his fifth season on the Tour for the world's top show jumpers.
"I'm just ecstatic, it's the first time I've won a Global Champions Tour Grand Prix, and I am just over the moon," Breen said in a televised interview. "Ipswich was just incredible, every jump, he just kept giving more, and giving more, and I thought, I was just enjoying it. It was lovely."
Breen, 43, said he realized he had to make up a little bit of time on Zorzi as he entered the last stretch of the six-horse jump-off in the small, technically challenging sandy arena in Monte Carlo.
"Then I thought, don't panic, we will just make it up somewhere," Breen said after producing a clear round in 35.56 seconds. "He is naturally quite quick, so when I jumped the second last, I saw a stride to the last, and I said 'here goes.'"
Watched by Prince Albert II of Monaco, his sister Princess Caroline and Microsoft founder Bill Gates, Zorzi set the pace with a clear round of 35.72 seconds. Ireland's Denis Lynch and RMF Bella Baloubet were in third place in 40.43 seconds.
Although Harrie Smolders of the Netherlands, the reigning overall champion, produced the fastest time (34.16 seconds) with Cas, he finished fourth with four penalties.
Born in Limerick, Ireland, Breen is now based in Hickstead, England. He got his first pony when he was five, and hunted throughout his childhood. He once said he became a show jumper "because I'd always been mad keen on horses, and I was desperate to get out of school."
Breem's Monaco victory means he has qualified for the lucrative playoffs in Prague at the end of December.
"It's fantastic, 18 riders go to it and I'm just so delighted, a huge pot of money there and I am just over the moon," said Breen.
Although the top three on the overall leaderboard, Edwina Tops-Alexander of Australia and Britons Ben Maher and Scott Brash, all competed in Monaco, none of them managed to reach the jump-off.
Brash and Maher both had four penalties, while Tops-Alexander had eight.
After nine of 16 legs, Tops-Alexander remains the overall leader with 186 points, followed by Maher with 172 points and Brash with 157 points.
Both Brash and Tops-Alexander are trying to become the first rider to win the overall LGCT title for a record third time.
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Earlier in the day, Rome Gladiators won the Longines Global Champions League team event after Belgium's Constant Van Paesschen and Brazil's Marlon Zanotelli each produced two clear rounds in the two-day team competition.
Maher and Switzerland's Marcus Fuchs of London Knights were second, followed by Smolders and Ireland's Mark McAuley of Montreal Diamonds.
Although the Knights remain the overall leaders with 199 points, followed by Valkenswaard United with 183 points, their Monaco victory means the Gladiators soared up the overall leaderboard to third place with 137 points.
Only the top 16 teams will qualify for the GC Play Offs and GCL Super Cup in Prague, where a record €12 million in prize money is up for grabs.
The next leg of the LGCT will be staged in Paris on 5-7 July.