Rio 2016: Joseph Schooling stuns Michael Phelps
Phelps was seeking his 23rd Olympic gold in the 100m butterfly but Schooling, 21, relegated the legendary American to silver.
Rio De Janeiro: Unheralded Singaporean Joseph Schooling stunned the great Michael Phelps in his final individual Olympic race in an almighty upset at the Rio Games on Friday.
Phelps was seeking his 23rd Olympic gold in the 100m butterfly but Schooling, 21, relegated the legendary American to silver -- which he shared with both Chad le Clos and Laszlo Cseh.
It was by far the biggest shock on a day of surprises, as 1,500m ace Sun Yang flopped out of his pet event and defending champions USA crashed out of the women's football.
Ethiopia's Almaz Ayana smashed the long-standing women's 10,000m record by nearly 14 seconds as the athletics competition got underway without Russia, whose track and field team are suspended over a doping scandal.
Elsewhere cyclist Bradley Wiggins became his country's most decorated Olympian of all time and Rafael Nadal, returning from a wrist injury, won men's doubles gold.
The Rio Games also reeled from three doping cases as a Chinese swimmer was suspended and a Bulgarian weightlifter and Polish runner were kicked out.
Victory in Friday's fly would have given Phelps a 14th individual Olympic title, but Schooling proved too strong.
Schooling, who took bronze at last year's world championships, punched the water and roared with delight as Phelps swam over to pat him on the back before le Clos ruffled the youngster's hair.
Katie Ledecky also made history as she completed the first 200m, 400m and 800m treble since 1968 -- and in world-record time.
America's latest swimming star won the 800m by a distance in a time of 8min 04.79sec, beating her own world record of 8:06.68 set in January.
'Bunch of cowards'
On the track, Ethiopia's Ayana set tongues wagging when she obliterated a record set in 1993 by timing 29min 17.45sec, 15 seconds ahead of Kenya's Vivian Cheruiyot in second.
Athletics is battling a torrent of doping controversies after world body the IAAF suspended Russia's track and field team and Kenya was threatened with the same treatment.
Ayana's record was greeted with suspicion by marathon world record-holder Paula Radcliffe, but the 24-year-old brushed off the speculation.
"My doping is my training, my doping is Jesus -- otherwise I'm crystal clear," she smiled.
Michelle Carter of the United States stunned defending champion Valerie Adams with her very last throw to win the gold medal in the women's shot put final.
Britain's Jessica Ennis-Hill made a strong start to her heptathlon title defence as she won the 100m hurdles, finished third in the high jump and second in the shot put to lie second overall.
French giant Teddy Riner, who stands 6ft 8in (2.04 metre) and weighs more than 300 pounds, won the men's +100kg judo by penalties from Japan's Hisayoshi Harasawa.
Earlier, Egyptian judoka Islam El Shehaby was jeered after refusing to shake hands with his Israeli opponent at the end of their heavyweight first round encounter.
Chen Xinyi, 18, a rising star in the Chinese swimming team, was suspended after she tested positive for a banned diuretic following Sunday's women's 100m butterfly, where she placed fourth.
The world sports tribunal had earlier expelled European champion weightlifter Tomasz Zielinksi and Bulgarian 3,000m steeplechase runner Silvia Danekova over doping as the Games registered its first major cases.
Chinese swimmer Sun's unhappy Olympics also came to a halt when he finished seventh in his heat and 16th overall in qualifying for the 1,500m, an event in which he has been untouchable.
In football, American goalkeeper Hope Solo lashed out at Sweden as "cowards" as the 2004, 2008 and 2012 women's football gold medallists and reigning world champions went out 4-3 on penalties.
"We played a bunch of cowards," Solo told Sports Illustrated.
"The better team did not win today. I strongly believe that. I think you saw American heart. You saw us give everything we had today."