Lena Schoneborn of Germany was the leader after two rounds of the Olympic women's modern pentathlon, one of the great all-round tests of an athlete's ability, on Friday.
An excellent fencing section, where she won 28 of her 35 bouts against the rest of the 36-strong field in a series of one-minute epee bouts, propelled Schoneborn, ranked third in the world, to the top of the standings.
Schoneborn, on 2,132 points, was 60 points ahead of 19-year-old Aya Medany of Egypt, silver medallist at the world championships in Budapest in June.
Belarus's Anastasia Samusevich was a further 36 points adrift in third while Britain's Heather Fell, with Prime Minister Gordon Brown watching on from the stands, was in fourth place - her final position in Budapest.
However, world champion Amelie Caze of France was down the field in 13th, her 22 wins placing her fifth in the fencing but not compensating for her score of 177 out of 200 in the 10-metre pistol target shooting.
Earlier, Sheila Taormina made history just by taking her first shot.
The 39-year-old American is competing in a record-breaking third different sport in her fourth Olympic Games.
She won gold as a swimmer in the 4x200 metres relay at the 1996 Games in Atlanta, before featuring in the triathlon in Sydney in 2000 and again four years ago in Athens.
However, the fencing proved tough for Taormina, whose four wins out a possible 35 left her bottom in that section and last in the overall standings.
The next event on the schedule, the 200 metres swimming, should be more to Taormina's liking.
From there athletes go on to compete in a 12-obstacle show-jumping competition where, unlike other Olympic equestrian events, they won't be riding their own horses.
Wet conditions, which caused heavy going, were blamed by officials for the several falls and multiple refusals which took place during the show-jumping phase in the men's pentathlon Thursday although some riders were critical of the quality of the horses provided by hosts China.
The cumulative points score after four events is converted into seconds of advantage ahead of the 3,000 metres where the overall leader is the first off in a staggered start.
This means that whoever is the first across the line is also the winner of the gold medal.
The modern pentathlon, a sport created by the French founder of the modern Olympics, Baron Pierre de Coubertin, is a demanding event featuring five disciplines based on the abilities that might have been expected of a military messenger in the army of Napoleon.