Beijing:Michael Phelps cemented his place in Olympics history on Sunday, capping a sensational week by becoming the first athlete ever to win eight gold medals in one Games.
Phelps brought the curtain down on a record-breaking week of swimming when he directed the US team to victory in the 4x100m medley relay and overtook fellow US legend Mark Spitz's seven gold medals at Munich 36 years ago.
The 23-year-old Phelps also broke seven world records through the week and became the most successful Olympian of all time with a career 14 gold medals.
"I'm lost for words," he said.
"The whole thing, every race, one after the other from winning by one-hundrerdth of a second yesterday to finishing if off with a world record. It's an amazing experience," he added, crediting the relay team for making it possible.
His butterfly leg was key to the relay victory, as he turned a third-place behind Japan and Australia at the halfway point into a lead which freestylist Jason Lezak would never surrender.
Daily superhuman performances saw Phelps constantly command centre stage in Beijing, although late Saturday the headlines switched to Jamaican Usain Bolt who underscored his place as the fastest man on earth when he won the prestigious 100m final.
Bolt surged down the track in 9.69sec, smashing his own world record and then declaring he has the 200m target in his sights as well.
China continue to dominate the medal table with 27 gold ahead of 17 for the United States of which Phelps has contributed nearly half.
Romanian mother of two Constantina Tomescu launched the Olympics busiest day Sunday when she raced away with the women's marathon in a time of 2hours 26minutes 44seconds.
There was more Olympic misery for Britain's world record holder Paula Radcliffe as she limped across the finish line in 23rd place.
There are 37 finals Sunday, four more in athletics including the womens 100m and men's 10,000m, as well tennis, badminton, cycling, diving, fencing, gymnastics, rowing, yachting, shooting, table tennis, weightlifting and wrestling.
The men's 10,000m final shapes as an Ethiopian clean sweep involving three outstanding athletes.
Kenenisa Bekele will be looking to defend his title from former champion Haile Gebrselassie and Sileshi Sihine, the silver medallist in Athens.
Kerron Stewart was shaping up for a Jamaican sprint double with Bolt, leading the favourites after the heats of the women's 100m.
In the pool the US relay team took more than 1.3sec off the previous world record while Australia clipped more than three seconds off the women's 4x100m relay record.
But for Australian Grant Hackett, his dream of an historic three 1500m freestyle golds at consecutive Olympics was snapped by Tunisia's Oussama Mellouli who, after nearly 15 minutes of racing, finished a mere 0.49sec ahead.
Incoming world tennis number one Rafael Nadal of Spain goes centre court when he plays Chilean Fernando Gonzalez in the men's singles final.
The women's final is an all-Russian affair between Elena Dementieva and Dinara Safina.
There are seven rowing finals including the women's eight where Romanian rower Georgeta Andrunache is on the brink of history as the sport's most successful Olympian.
She won the women's pairs with Viorica Susanu on Saturday for a fifth career gold, level with rowing legends Steve Redgrave and Elisabeta Lipa, and another victory will give her sole rights to the record.
British cyclist Rebecca Romero is also assured a place in women's history for winning medals in two different sports.
A rowing silver medallist in Athens four years ago, Romero rides off in the final of the women's individual pursuit Sunday.
The only other sports double was achieved by American Tim Shaw who won a swimming silver in 1976 and a water polo silver in 1984.