Great Britain missed out on further equestrian eventing medals in the individual competition as Germany's Michael Jung made history by taking gold.
Mary King and Tina Cook had earlier played their part in earning GB silver medals in the team event and the pair went into the second showjumping round - which would determine the individual placings - in third and fourth place respectively.
However, both put two fences down as Jung bcame the first rider ever to hold Olympic, world and European titles at the same time.
King finished fifth and Cook - the bronze medallist in Beijing four years ago - sixth, while Zara Phillips, who did ride a clear second round, was eighth.
Jung made history with his clear round - he had also gone clear in the first showjumping run and Monday's cross-country meaning his winning score of 40.30 was entirely accrued in the dressage.
However, it was a nail-biting finish.
After is clear round, Jung had to watch the final competitor, Sweden's Sara Algotsson Ostholt, before knowing whether he would be crowned champion or not.
Algotsson Ostholt knew a clear round would see her become the first ever female to win the individual eventing gold but she put down the very last fence and had to settle for silver.
Jung's team-mate, Sandra Auffarth, claimed the bronze - more glory for Germany after their earlier success in the team competition.
The disappointed King, competing in her sixth Olympics, knew the reason for her slip-up - riding too close to the bronze statue of a lion before starting jumping.
She said: "Stupidly, I rode near it and it really frightened him (horse Imperial Cavalier), not surprisingly.''
"When they rang the bell he was strong and a bit nervous,'' added King. "I should have circled. It was a mistake I made.''
King, however, has no intention of hanging up her riding boots just yet.
She said: "I hope to be in Rio. I have no visions of stopping yet. I love the sport. I am fit and healthy though getting old and I love it. You've got Mark Todd (who won bronze for New Zealand and is 56) even older than me and still loving the sport.
"My daughter (Emily) is keen to ride in my footsteps and her dream is for us to ride in the team together, although she may be a bit young for Rio.''