Sally Pearson of Australia set a new Olympics record to win the gold in the women's 100 metres hurdles while reinstated Algerian Taoufik Makhloufi produced a stunning burst in the last 300 meters to be proclaimed the men's 1,500 metres champion.
Pearson, the silver medallist four years ago, clocked 12.35 metres and finished two-hundredths of a second ahead of defending Olympics champion Dawn Harper, who took silver while Kellie Wells claimed the bronze Tuesday.
The rain fell in buckets as the runners lined up on the blocks but Pearson, who had been pre-race favourite, got off to a flying start with Harper and Wells close behind, Xinhua reported.
"It's a dream. Relief was the first thing I felt and then shock. I'm just going through the emotions. I really wanted this. I've worked so hard for two years. To see my name on the scoreboard, I just can't believe it," said Pearson, who said she had been inspired by the great Australian athlete, Cathy Freeman.
Harper had run a personal best of 12.46 in her semifinal earlier in the evening, but it was Wells, who was Pearson's closest pursuer in the opening metres of the race.
Harper then found an extra turn of speed and was closing on the Australian, but Pearson timed her dip to the line to perfection. She had run 12.39, the fastest time of the year to date in her semifinal and she went even faster to claim gold.
There was an agonising wait for the results' confimation and when it was declared, Pearson threw herself to the ground in ecstasy. It was Australia's first track and field gold of the London Games.
Makhloufi produced a stunning run in the closing stages of the 1,500 meters final.
Makhoufi finished ahead of Leonel Manzano of the USA and Morocco's Abdaali Iguider and deserved his prize for an audacious final lap which saw him sprint away from the rest of the field.
The Algerian was a slightly controversial runner given that Monday had seen him excluded from the competition for allegedly not making an effort in the 800 metres heats. However, on appeal he was reinstated after a doctor confirmed he had a legitimate medical reason for retiring from the race. Whatever the problem, he made a miraculous recovery, although he insisted there was a problem.
"I have a problem with my left leg and it may need surgery," said Makhoufi. "It was the will of God, yesterday I was out, today I was in," he added.
Meanwhile, the Kenyan trio of reigning Olympics and World champion Asbel Kiprop, Daegu-runner up Silas Kiplagat and Kiplimo Chepseba all disappointed with Kiplagat seventh, Chepseba eleventh and Kiprop last.
The men's high-jump final was won by Russia's Ivan Ukhov, who gave a stunning display of jumping, clearing heights of 2.33m, 2.36 and 2.38 at the first attempt. With the gold medal assured, Urkov then made one attempt for a new Olympic record of 2.40, before deciding he would be better off celebrating his triumph and renouncing his two remaining attempts.
Erik Kynard took silver with a jump of 2.33, while three athletes tied for bronze: Mutaz Barshimi from Qatar, Derek Drouin of Canada and Great Britain's Robert Grabarz, all of whom cleared 2,29, but failed at 2.33. It is very rare indeed to see three people share an Olympic medal and the podium will be a very crowded place for the medal ceremony Wednesday.
Robert Harting went into the final of the men's discus on the back of 28 consecutive victories stretching back to August 2010.
The German's fifth throw of 68.03 was enough to give him gold ahead of Ehsan Hadadi of Iran, who added Olympic silver to the World Championship bronze he won in Daegu last year with a throw of 68.18, while Estonia's Gerd Kanter picked the right moment to throw a season's best of 68.03 as it brought him the bronze.
Reigning women's 200 metrs Olympic Champion Veronica Campbell Brown produced a season's best of 22.32 as she advanced into Wednesday's final.
Eight times world champion, Alison Felix won the second heat in the same time with Ivory Coast sprinter, Muriette Ahoure second.