Russia's Olga Kaniskina defied torrential rain to record an emphatic gun to tape victory and shatter the Olympic record by more than two and a half minutes.
Kaniskina started clear favourite to add the Olympic title to her World crown from last year and she lived up to those high expectations to take victory in 1:26:31.
Behind her Kjersti Platzer, 36, of Norway became the oldest woman to win an Olympic medal in the 20km walk by taking silver in a national record of 1:27:07.
The bronze went to the fast finishing Elisa Riguado, who posted an Italian record of 1:27:12. But there was frustration for the host nation as Hong Liu of China just missed out on a medal, finishing fourth in 1:27:17.
For Kaniskina, aged just 23, it was the perfect demonstration of her stranglehold on the world of race walking and in her post-race interview she dismissed the weather conditions as an irrelevance.
"It had no influence on me," Kaniskina explained. "It was better than a sunny or a hot day."
Kaniskina certainly did not start like an athlete with any concerns at the incessant rain thrashing down on the Chinese capital as she established a 50m lead from Riguado, the European bronze medallist, before leaving the Bird's Nest Stadium to start nine 2km loops around the Olympic Green.
The diminuntive Kaniskina continued to pile on the agony for the opposition and at 6km had opened up a 37-second lead on her rivals.
However, such was her eagerness to secure gold she was given an early penalty for lifting. Spain's Maria Vasco headed a group of 11 athletes in the chasing group.
Kaniskina, though, by the 10km mark - which she passed in 42:43 - had opened up a 46-second gap on the pursuing pack and was showing no signs of weakness.
The chase group had been whittled down to six athletes, headed by European champion Ryta Turava of Belarus and also including, Vasco, the Chinese duo Liu and Mingxia Yang, Platzer and the 18-year-old Russian prodigy Tatyana Kalmykova.
Yang's challenge, however, was over in the early stages of the second half of the race after she was disqualified for lifting and Kalmykova's race also ended prematurely as she, too, fell foul of the judges.
While Kaniskina maintained her relentless pace at the front - she passed 14km in 59:51 some 48 seconds clear - gaps started to appear behind.
Turava had opened a 12-second lead in the silver medal position ahead of Platzer and Vasco, who were matching each other stride for stride, with Beatriz Pascual of Spain in fifth.
As the deluge from the skies continued remorselessly so did Kaniskina's advantage.
However, the race for the minor medals took a dramatic twist after 1:14. Turava looking in a distressed state stopped briefly and as Platzer and Vasco swept past her the Belarussian's medal challenge quickly evaporated.
Kaniskina hit 18km in 1:17:24 - some 1:01 ahead of Platzer, who herself was starting to draw ahead of Vasco in the race for silver, with Riguado now threatening the bronze medal position.
In the final 2km a badly fatigued Vasco was swamped by first Riguado and then Liu as the Spaniard dropped to fifth.
Up front, however, nothing was going to deny the formidable Kaniskina. Platzer, who also won Olympic silver at the 2000 Sydney Games, was being hunted down by a charging Riguado in the latter stages but the Norwegian held on for silver and the Italian was rewarded for her well timed challenge with the bronze.
Liu could not quite deliver the medal the home crowd craved, but she can be proud of her efforts to finish fourth. Vasco was desperately disappointed to finish out of the medals in fifth - although she had the consolation of setting a national record of 1:27:25.
Her countrywoman Pascual set a PB of 1:24:44 for sixth. One second further back in seventh Ireland's Olive Loughnane set a PB while Portugal's Ana Cabecinha grabbed eighth in a national record of 1:27:46.
As a further indication of the overall quality of the race the 2004 Olympic champion Athanasia Tsoumeleka set a national record of 1:27:54 - a time only good enough for ninth in her title defence - and some 12 women dipped below the previous Olympic record of 1:29:05 set at the 2000 Sydney Olympics by China's Wang Lipang.
Turava faded out of contention in the final few kilometres and finished 11th in 1:28:26.
Steve Landells for the IAAF