We gathered by the Great Wall of China to see if Britain's new cycling star Nicole Cooke could add a second gold to the one she had won so courageously on Sunday - but instead ended up saluting another heroine following the sensational silver medal-winning race of a lifetime from her unsung little team-mate, Emma Pooley.

On Sunday, in the driving rain and cool conditions around this murderous, undulating course, it had been Pooley who had acted so selflessly for her colleague Cooke, making the break on the hills which, as she eventually cracked and finished 23rd, ultimately paved the way for the Welsh woman to become Britain's first female cycling champion.

Yet today in completely contrasting conditions, with the stifling, humid air sucking the breath out of every rider, the 5ft 2in Pooley, whose strength belies her slight frame, finally got her just desserts, riding herself "to the point of sickness" over the 14-and-a-half mile course at an incredible average speed of 40 km per hour to finish second in her specialist time trial event.

"It was the hardest race of my life," she could only gasp. And an hour later, she was able to pronounce it the best race of her life too as she clutched the medal which represented an amazing achievement for a converted triathlete who's only been a professional for two years.

She had started fifth in the 25-strong field - they all set off two minutes apart - and had posted a scintillating time of 35min 16.01sec to establish a formidable target which, for much of the morning, looked as if it could be good enough to make her the gold medallist until one last supreme effort from American Kristin Armstrong.

For Cooke, the exertions of Sunday's triumph appeared to have completely drained her as she struggled home 15th and immediately slumped to the ground with exhaustion at the line - but she would have been the first to feel delight for her 25-year-old colleague who had been, she admitted, indispensable to her golden success.

This time, though, there could be no strategy, no teamwork. It was just one woman, a bike and the clock - and, on a day where it must have been nightmarishly hard work even just to be a tourist here strolling up the ramparts of the Wall, this could only have been hell on wheels.

Yet what was so striking about Wandsworth girl Pooley's effort was that she is so diminutive and light that, in theory, she shouldn't have been able to challenge the physically much bigger and stronger rivals who specialise in this brutal race against the clock. What an illusion that proved in the haze.

The woman described by former Olympic champ Chris Boardman as a "great little climber" just seemed to fly up the hills. "Chris also said 'she doesn't have much power', which p***** me off a bit," laughed Pooley, disproving that theory too as she sped to the line beneath the Juyongguan Pass so tirelessly that she almost caught the Russian rider who started four minutes ahead of her.

It was then it dawned on the Cambridge engineering graduate that she'd done something fairly spectacular over one of the most picturesque courses ever to stage Olympic road racing between the two most popular tourist sections of the Wall, at Badaling and Juyongguan.

Not that she'd been able to appreciate that fact as she stood hunched, drenched in sweat and as pale as a ghost.

"I was almost sick on the line. It's like you'll never be able to breathe again at the end. Obviously I was a bit tired after Sunday's race but I left nothing out there," she said. "There's no secret; you just have to make it hurt. Imagine a friend sitting on your wheel, shouting at you."

Still, she was left with an anxious wait, happy to chat away to journalists in a bid to distract herself, as world-class rider after world-class rider struggled through to the line without getting within 25 seconds of her time.

Ultimately, though, with just six riders still out on the course, it was the woman with a fabled cycling name, 35-year-old former world champ Armstrong, who spoiled the prospect of Britain's third gold of the Games with an astounding ride, finishing nearly 25 seconds quicker than Pooley after a breathtaking second half of the race.

The GB team couldn't have been happier for Pooley, saying that she had merited the medal for her sacrifice on Sunday but she wasn't having any of it.

"Don't big me up - I wasn't that selfless. If my break had come off, I'd have won a medal," she smiled. "It helped Nicole and it could have worked for me - but I wouldn't say I'm a saint."

Once again this had not just been a triumph for an individual British cyclist, but for the entire team as the Zurich-based Pooley explained how she had not just managed to succeed on her own heart and guts but also because of some familiar appliance of space-age science from the best-prepared squad in British sport.

For the first time in competition, she rode gripping a new pair of what she described as "funky handlebars" designed by the British cycling technicians. The idea was to make her body position more comfortable as she tried to be aerodynamically as efficient as possible while negotiating the steep descents following the crushing 11km climb.

"I thought I'd be scared going so fast down the hills but actually I wasn't at all," she smiled. "It was really fun and I just kept saying to myself 'faster, faster'." Pooley did keep getting faster and faster to the point that she wrote another grand chapter in the British women's success story at these Games.