Keri-anne Payne emerged battered from the Serpentine as Britain's disappointing swimming campaign continued with their third fourth-place finish of the Games.
As with Payne's good friend and bridesmaid Rebecca Adlington, there had been a degree of expectation that victory was a formality.
Given the vagaries of sport as well as the varying conditions in which open water is held, this was never going to be straightforward.
However, there was widespread surprise Payne did not add to her world and Olympic medals as she was out-muscled, despite looking like she might reel in third-place finisher Martina Grimaldi at the death.
The 24-year-old fell just short as Hungary's Eva Risztov held off the fast-finishing American Haley Anderson for victory in one hour 57 minutes 38.2 seconds, four seconds ahead of Payne who was 0.4secs short of Grimaldi in third.
The Stockport ITC swimmer fought until the bitter end today but she fell short, her energy sapped by a stop at the feeding station on the third lap and the subsequent battle to get back among the contenders.
The Johannesburg-born swimmer is as composed out of the water as she is committed in it but her mask fell when she spotted former training partner and Athens bronze medallist Steve Parry.
She sobbed before composing herself again, saying: "I thought I was all right to be honest when I was walking around until I saw Steve.
"He has been such a huge part of my life, training with him at Stockport, he used to take me there every morning and things like that.
"You're fine and then you see someone that really does mean something to you and it brings it all back."
Struggling to hold back the tears, Payne admitted the race had been far tougher than she had envisaged with both Risztov and Grimaldi blocking any attempted move by the Briton.
She said: "It seemed to be a pretty tough, violent race from the start.
"I'm not really a fighter - I'm more of a lover I guess.
"I struggled in the pack with all the fighting that happened, there was quite a lot of yellow cards handed out and I got hit quite a few times in the face.
"I tried to deal with it as best I could but it just took a lot more energy out of me than I was expecting it to."
Payne is renowned for going out fast and here she went straight to the head of the 25-strong field.
It is a tactic that has proved effective for the double world champion and 2008 silver medallist, enabling her to stay clear of the maelstrom that can unfold with its attendant kicking and hitting, some of it deliberate, some not.
However, today she could not break free and head the field, her opponents snapping away at her.
Looking on was fiance David Carry, the 400m freestyle finalist, who she will marry in the autumn as well as double bronze medallist Adlington, a bridesmaid.
The pair flanked prime minister David Cameron who was no doubt hoping for another British victory.
However, it was not to be, Payne philosophical but tearful, dashing off to embrace Carry.
Now she will concentrate on her wedding while taking a break from 10km swimming but taking on more mile swims.
"Whatever is meant to be is meant to be and I guess I was meant to be fourth today," she said.
"I couldn't have done any more than I did today but open water is about who makes the right decisions at the right times and the top three girls, I can't be upset with them winning.
"It's not like they don't deserve it because every single one of them does."
Much had been expected of Payne, and it all started well on what was one of the hottest days of the Olympics at around 23 degrees.
And with the water temperature at the 20 degree-mark and no chop or current, conditions were ideal.
At the end of the first lap, Risztov, who returned to swimming in 2009 after a four-year break following her second Olympics in 2004, was leading in a tightly-bunched group of four.
Australia's Melissa Gorman was second through ahead of Payne and Anderson.
Payne and Risztov were swimming virtually on top of each other, leaving Anderson with a clear run to lead after two laps, with only 12 seconds separating 23 of the 24-strong field.
However, the fateful third lap saw the Briton in fourth at halfway only to drop a place over the following two laps.
Payne fought her way back on the last lap and her sprint finish saw her reel in Grimaldi in the final metres but fall just short.
Risztov also appeared to be about to be usurped by Anderson but held on as the American claimed her family's second medal of London 2012 with her sister Alyssa having taken gold byswimming in the heats of the triumphant 4x200m freestyle relay.
It has been a disappointing performance by the British swimmers, with national performance director Michael Scott last week admitting it had fallen short of expectation.
Adlington claimed two bronze medals while Michael Jamieson's superb silver was a rare ray of sunshine.
However, they cannot now match their base target of five agreed with UK Sport with just three medals earned and one swim remaining, Daniel Fogg in the men's 10km.
It also contrasts most unfavourably with Beijing where they claimed six medals in total.
A full review will be launched which could well see difficult questions asked of David Sparkes, British Swimming chief executive, with the sport the fourth-best funded in the UK to the tune of £25million per year.
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