Stephanie Cook claimed Britain's 11th gold medal of the Sydney games in the modern pentathlon.

Cook had to overturn a 49-second disadvantage on the cross country run to snatch the first women's Olympic title from the American Emily de Riel.

Team-mate Kate Allenby, who had started second in the fifth and final event, was overhauled by Cook but clung on to third place.

Cook, who postponed her medical career for a year to bid for Games glory, was lying eighth overall going into the fifth discipline in Sydney's Baseball Stadium.

But the Irvine-born doctor passed her examination as she used her running superiority to make up the deficit on the 3km cross country run.

Cook had been lying 14th following the swimming discipline during which Allenby had moved into second place overall.

Allenby held on to that position in the showjumping while Cook, who like her team-mate is now based in Bath, improved her overall position by six places.

The British duo held their own in the fencing event as the specialist tuition they had been receiving for the past few months paid off.

Cook said: "I am absolutely thrilled to bits. I can't believe it. I just want to thank all my coaches, physios and masseurs. Everybody has been fantastic.

"It has just been a day that I don't think anybody is going to forget in a hurry."

Allenby said: "It's a fantastic way to end the Games with two medals. I'm so chuffed and I'm so proud of Steph. She has worked so hard.

"Just watching her in training is something else. She pushes herself so hard and she deserves every second of this."

Team manager Dominic Mahony said: "To be honest we knew the jumping would sort the pentathletes out and we were confident we had two strong runners.

"They did a great job in the fencing and we were just looking at them getting a clean ride in the showjumping, knowing what Steph would do in the run.

"Kate did a great job staying out in front in the run and it was just a matter of time before Steph would get up with her."