Czech David Svoboda won gold in the men's modern pentathlon as British duo Nick Woodbridge and Sam Weale could only finish 10th and 13th.
The home pair went into the final event, the combined run and shoot, in the top 10 but they could not make up ground on the leaders in front of a huge crowd at Greenwich Park.
Svoboda, the 2010 European champion, went into the combined event in first place and overhauled China's Cao Zhongrong on the final one-kilometre run while Adam Marosi of Hungary won bronze.
Woodbridge's 10th place matched the finish of Weale in Beijing, which was the best by a British man for 16 years.
In the first event of the day, the fencing, Woodbridge and Weale both finished with 17 wins from 35 fencing bouts at the Copper Box, which was a little below par, for Woodbridge in particular.
The world number nine was on top form to start with, winning his first five bouts and at one stage topping the leaderboard, but he tailed off rather and had to settle for joint 13th.
The format in pentathlon involves each of the 36 men fighting each other in one-minute bouts, with one hit enough for victory.
Weale's morning progressed in the opposite way to his team-mate's, with the 30-year-old losing seven of his first nine bouts but recovering to finish in the top half of the field.
Next up was the 200 metres freestyle swim at the Aquatics Centre, which is one of Woodbridge's best events, and his time of one minute 57.32 seconds was the second fastest of the day and enough to move him up to eighth place.
Weale swum his fastest time of the year, 2min 03.40sec, while the event was won by Egypt's Amro El Geziry, who broke his own Olympic record with a time of 1min 55.70sec.
Svoboda was the leading athlete in the fencing, the Czech equalling the Olympic record with 26 victories for 1024 points.
The show jumping is often a game changer, with the athletes drawing their horses at random and having only 20 minutes to acquaint themselves with their animal.
Woodbridge and Weale both performed well to keep themselves in contention, knocking down one fence apiece, although Woodbridge did rack up quite a few time faults.
His score of 1156 was enough to lift him into seventh place, while Weale was ninth after accumulating 1176 points, the seventh best ride of the day.
Hungarian duo Robert Kasza and Marosi both managed clear rounds, as did Italy's European champion Riccardo De Luca.