Aron Szilagyi won gold in the men's sabre,
beating Italian Diego Occhiuzzi 15-8 in the final at the ExCel centre.
The 22-year-old proved too strong for the 2008 Olympic bronze medallist, racing to a 7-0 lead.
But Occhiuzzi, 31, came out fighting and won the first four points after the one minute interval.
The Hungarian regained his composure and eventually secured his country's first gold medal of the games.
Russian Nikolay Kovalev, who was beaten by Szilagyi in the semi-final,
took bronze after beating Romanian Rares Dumitrescu 15-10
in the third place play-off.
The 25-year-old had taken gold in the last three world championships but was unable to add Olympic gold to his tally.
Olympic men's fencing: James Honeybone out in opening round
The main talking point before the competition was the rivalry between two of the gold medal favourites - German Nicolas Limbach and Alexey Yakimenko of Russia - but both failed to live up to expectations.
The German reached the quarter-finals before he was beaten by Kovalev, while Yakimenko went out in the third round, beaten 15-14 by American Daryl Homer.
Britain's sole competitor in the event was 21-year-old James Honeybone, who was beaten 15-9 in the first round by Belarus fencer Valery Pryiemka.
Honeybone said: "I have a massive experience to take away from the Games, it just would have been nicer to have more competition experience."