Team GB archer Naomi Folkard exited the women's individual competition, losing in the last 32 to Mariana Avitia on Tuesday.
Kidderminster bowman Folkard had performed well to claim a hard-earned victory in the first elimination phase, taking down Russia's Kristina Timofeeva 6-4, but was out-shot by her Mexican opponent in the next stage.
Avitia, ranked 10th in the competition to Folkard's 42nd, was a 6-2 winner against the home favourite - winning the middle two sets and drawing the first and last.Folkard took a lead on the opening arrows, shooting nine to her opponent's eight but although the Briton's second shot landed in the centre, successive maximums from Avitia ensured a drawn first set.
The Mexican continued her good form in the second set, again reeling off successive 10s followed by a nine.
Folkard shot well, including one inner ring of her own, but could not do enough to prevent falling 3-1 behind.
Avitia's next three shots tallied 27 from a possible 30 and a closing eight left Folkard one short to lose two more set points.
She needed to win the next to extend her stay at the Games but another slip into the eight ring saw her halve the fifth for a 6-2 loss.
The 28-year-old, in her third Olympics, had earlier impressed against the highly-rated Timofeeva.
Russia had knocked Team GB's three out in the women's team event but Folkard was able to exact a measure of revenge with her 6-4 win.
She started nervily with a wide seven and lost the opening set but took advantage of two eights by her rival to go level at 2-2.
A perfect set of 10, 10, 10 restored Timofeeva's lead but Folkard showed her nerve to take the next two sets to set up her match against Avitia.
Folkard blamed her early exit on a poor qualifying performance.
"I should have qualified higher. My ranking wasn't good enough and that's why I've gone out at this stage,'' she said.
"I shot well this morning on the practice range and when I came in I still had some really good shots.
"I did feel nervous but I was in control. When I stood on the line I felt strong and I wasn't shaking.
"It was sort of perfect apart from the fact I didn't win, but Avitia was incredible. She shot really well.''
Alison Williamson, one of the record-equalling six-time British Olympians on duty in London, followed Folkard out of the competition with a first-round defeat.
Having placed a disappointing 47th in the ranking round, she faced the 18th seed - Mongolia's Bishindee Urantungalag - in the last 64.
Stafford-based Williamson won the first set with 27 from a possible 30 points but eventually fell to a 7-3 defeat as Urantungalag won the last three sets.Urantungalag found the seven ring with the first arrow of the match and when Williamson followed with a nine and a 10, the first set was on its way to the host nation.
Williamson's form held at the start of the second, hitting centre and outer gold to leave her with the prospect of a nine to go 4-0 in front.
Instead the struck eight to halve the set.
A high seven followed, costing her set three and her aim wavered thereafter, with three of her next six arrows going for wide eights either side of the target.
By that time her opponent had tightened up her game, shooting 28 and 27 in the last two sets to secure a place in the last 32.
Williamson has not yet ruled out competing in a seventh Games in Rio in 2016.
"Age isn't a barrier to competing at the highest level,'' she said.
"But I'm going to have to sit down and think what my future holds.
"I'm probably going to have to look for a job, so if anyone wants to employ a six-time Olympian who can do a bit of archery then I'm your candidate.''
Tuesday's results mean Amy Oliver is GB's last remaining hope. She begins her challenge on Wednesday but faces a tough task against world number one Deepika Kumari.
