Great Britain picked up their first medal of the 2004 Olympics on the opening day in Athens.
Peter Waterfield and Leon Taylor claimed a superb silver in the men's synchronised 10m platform diving.
Elsewhere, Michael Phelps began his quest for a record eight gold medals with victory in the 400m individual medley, breaking his own world record.
But the day has been overshadowed by the controversy surrounding sprinters Kostas Kenteris and Katerina Thanou.
They have now been withdrawn from the Games by Greek team officials, pending an International Olympic Committee hearing on Monday after missing a drugs test on Thursday.
Phelps went some way to ensuring the first day of the Games would be also memorable for sporting achievement, beating compatriot Erik Vendt and Hungary's Laszlo Cseh into silver and bronze respectively to clinch his first ever Olympic gold medal.
Less than 30 minutes later, Australian rival Ian Thorpe picked up the first of a possible six gold medals in the 400m freestyle.
Thorpe shed tears at the end after holding off a fast-finishing Grant Hackett in the final 50m, with Klete Keller of the United States taking bronze.
British hopefuls Adam Faulkner and Graeme Smith earlier failed to reach the final.
But there was better news for Darren Mew and James Gibson, who both qualified for the 100m breaststroke final.
In the women's 4x100m freestyle relay, Australia broke the world record as they saw off the United States to take gold.
Great Britain fell just short of breaking the national record in finishing a creditable sixth.
Ukraine's Yana Klochkova successfully defended her Olympic 400m individual medley title, but she was made to battle all the way by Kaitlin Sandeno of the United States, winning by just 0.12 seconds.
In the first diving final, Britain narrowly missed out on a medal, Jane Smith and Tandi Gerrard finishing fourth in the women's 3m synchronised springboard.
On the water, Ben Ainslie's hopes of following his gold medal in Sydney with a second in Athens suffered a blow.
The Briton finished a disappointing ninth in the Finn first round, but appeared to have got his challenge back on track by finishing second in round two.
However, he was later disqualified and now languishes in 19th place overall, but Britain's Nick Rogers and Joe Glanfield top the standings after two races in the 470 class.
Britain's rowing flagship - the coxless four - got their gold-medal campaign off to a confident start with victory in their heat.
Watched by Prime Minister Tony Blair, the quartet of Matthew Pinsent, James Cracknell, Steve Williams and Ed Coode held off the sprightly Italian four.
Team GB's other leading medal hope - the coxless pair of Katherine Grainger and Cath Bishop - grabbed second spot in their heat but were a long way off the pace of favourites Belarus.
In cycling, Italy's Paolo Bettini became the Olympic road race champion, beating surprise package Sergio Paulinho of Portugal in a sprint finish.
Axel Merckx, son of Belgian cycling legend Eddy, broke away from the peloton to clinch bronze.
The first gold of the Olympics was won by China's Du Li in the women's 10m air rifle final, and China completed the double in the event when Wang Yifu won gold in the men's version with his final shot.
In weightlifting, Nurcan Taylan made history by becoming the first woman to win gold for Turkey.
Taylan hoisted a world record combined total of 210kg to triumph in the 48kg category.
Great Britain had a realistic chance of the top prize in the men's under-60kg judo, with England's Commonwealth champion Craig Fallon flying the flag.
He opened well, winning his opening bout against Scott Fernandis with ippon after just 35 seconds, but his medal hopes were then dashed by Revazi Zintiridis, again by ippon.
The gold medal was eventually won by Tadahiro Nomura of Japan, who became the first ever triple Olympic champion in judo.
Britain endured a faltering start in the shooting, with Ian Peel and Ed Ling unlikely to reach the final of the trap competition after ending Saturday's three rounds with scores of 70 and 69 respectively.