By Bryn Palmer, Sydney

Stephanie Cook reflected on the sabbatical that saw her swap medicine for the modern pentathlon and admitted: "I think I might need to sit down and re-assess my life after this."

The 28-year-old Scot secured her place in Olympic history by shooting, fencing, swimming, show-jumping and running her way to gold in the inaugural five-discipline event for women at the Games.

Fellow Briton Kate Allenby also took a battling bronze in the final event in Sydney to complete Britain's best Olympics medal haul since Los Angeles in 1984.

For Cook, a junior doctor, it fully vindicated a decision to put her medical career on hold a year ago and, with the benefit of Lottery funding, devote herself full-time to the pursuit of a medal at the first Olympics to contain a modern pentathlon for women.

A talented all-round athlete who rowed competitively during her Cambridge University days and was a good enough runner to finish seventh in the national cross-country championships three years ago, her strength in the latter ultimately brought her greatest reward.

Having finished the opening shooting section in eighth place, she slipped to 14th despite a much-improved display in her weakest discipline, fencing, where she remained despite beating her personal best in the 200m freestyle swim by a second.

Even after a superb round in the show-jumping, where she knocked just two fences down, Cook was still only eighth, which in pentathlon terms meant she started on the final 3,000m run 49 seconds behind the leader, the USA's Emily de Riel.

But Cook set off in the reassuring knowledge that she had previously made up a deficit of more than a minute on the American girl at the world championships this year, and had already moved up from eighth up to third after the first 1000m.

After the second 1000m she was only seven seconds adrift of Allenby, who had started in second place and stayed close on de Riel's heels early on, swiftly overtaking her team-mate before advancing past the American with around 400m to go and stretching away to victory.

"Running has always been strong point and I always believed I could do it, but it was never going to be easy," she said later.

"It was just a question of pacing it right and making up the ground. One of the best bits was getting into a medal position but I still had a lot of work to do. But once I have passed somebody, I know they are not going to come back past me again."

That confidence was clearly not misplaced. De Riel, who Cook labelled an "honorary Brit" - the pair started the modern pentathlon together during their post-graduate studies at Oxford University - confirmed as much when she admitted: "I was waiting for Steph to pass me."

Having originally decided to combine a research post at a Guildford hospital with her Olympic aspirations, the news that her application for Lottery funding had been granted allowed Cook to train full-time, along with Allenby, at Britain's new pentathlon training centre in Bath.

She admits her intention was to give herself a year off to prepare for Sydney, but may now decide to remain a full-time pentathlete with the world championships due to take place in Britain next July.

"I only ever dreamed that this might happen, so I really don't know what is going to happen from now on," she said. "I think I will probably go on to the world championships now, but I think I might need to sit down and re-assess my life after this."

Allenby, 26, who received a warm embrace from Cook after collapsing over the finish line, was full of admiration for her colleague's achievement.

"She works so hard," she said. "She is so dedicated. Just watching her training is something else. She pushes herself so hard and she deserves every second of this success."

Britain's team manager Dominic Mahony, a bronze medalist in the men's team event in Seoul 12 years ago, paid tribute to both women, insisting their success was further evidence that the Britain's world-class performance programme was reaping the rewards.

"People shouldn't have been surprised by this success," he said.

"We have been able to bring in coaches from around the world like Jan Bartu (a Czech), who runs our national programme in Bath, and we are going to have more success. We daren't hope too hard for two medals, but I am not surprised we have got gold.

"These two were adversaries today, fighting against each other, but you could see at the end they are good team-mates as well.

"Kate hasn't had an easy build-up running and swimming-wise, but she swam brilliantly and really held it together in the run as well.

"Steph has been in such great shape in the last few weeks - we really did think she was going to do it. We were a little bit concerned when the gap stayed at 16 seconds on the second lap but she really turned on the power in the last 500m."