Nineteen-year-old Joe Evans claimed a bronze medal at his first Modern Pentathlon World Cup in Palm Springs.
The University of Bath student crossed the finishing line just eight seconds behind the world champion, Alexander Lesun of Russia, and two seconds adrift of Hungary's Olympic bronze medallist, Adam Marosi.
British team-mates Jamie Cooke and Sam Curry finished 18th and 23rd, the latter on his World Cup debut.
"The result is absolutely amazing," said Evans. "I'm not sure how it happened, but I'm so pleased."
Jan Bartu, Pentathlon GB's performance director, said: "It's Joe's first World Cup appearance, his first progress to the final stage and now first medal – rock and roll for the world-class performance pathway."
Evans was in joint eighth place after the fencing and his freestyle swim was fifth fastest at 2hr 01.69min, allowing him to climb to joint sixth.
On a day when only one rider, Ireland's Eanna Bailey, managed to go clear in the allowed time, Evans dropped just 40 points to go into the combined run-and-shoot in second place, five seconds behind the leader, Amro El Geziry of Egypt.
His run-and-shoot time was the 22nd fastest of the day, but it was enough to ensure he finished 10 seconds clear of Russia's world No 2 Ilia Frolov.