Iran defied the Olympic spirit of sport without frontiers on Sunday by refusing a judo fight against an Israeli at the Athens Games, insisting on putting political solidarity with the Palestinians before gold medals.
In the pool, U.S. swimming phenomenen Michael Phelps, 19, was forced to concede early defeat in his bid for a record eight Olympic golds and the highly fancied American basketball team were upset 92-73 by Puerto Rico.
It was the first loss at the Games by the Americans since 1988.
Olympic judo officials met in emergency session to decide how to handle world champion Arash Miresmaeili's failure to compete against Israeli Ehud Vaks. It reached no immediate conclusion.
A homegrown scandal also rumbled on, with Greece's two top sprinters saying they would miss an appeal hearing on Monday that may bar them from the Games for missing drugs tests.
An ignominious exit from the Games by the Greek pair looked increasingly inevitable. But the burning issue in the judo row was whether any penalty would hit Miresmaeili alone or Iran's entire team.
There was more drama in the swimming pool when South Africa ruined American sensation Phelps's dream of surpassing countryman Mark Spitz's record seven golds at the 1972 Munich Games. Phelps had won the 400 individual medley on Saturday in world record time.
The South African quartet's stunning victory in the men's 4x100 metres freestyle final in three minutes 13.17 seconds wiped half a second off the old world record set by Australia at the last Olympics.
Australia's Ian Thorpe earlier won round one of a duel with Phelps in the 200 metres freestyle. But the reigning Olympic champion from the Netherlands, Pieter van den Hoogenband, outpaced both to qualify fastest for Monday's final.
French teenager Laure Manaudou won the women's 400 metres freestyle to give France its first gold, becoming the first Frenchwoman to win an Olympic swimming title.
On the second day of full competition, Athens was blasted by a hot, hair-dryer wind that threatened to spook horses at the equestrian events and played tricks at the archery.
The rowing regatta had to be stopped altogether, prompting some told-you-so comments from critics who said it was located in the wrong place to begin with --
But the gusting winds could not stop Russia's Alexei Alipov winning gold in the men's trap shooting with a near-flawless performance on a range carved into a mountain top.
The 29-year-old Muscovite scored 149 out of 150, including a perfect 25 in the final round. It gave the Olympic giants their first gold of these Games and Moscow claimed it was its 500th overall, counting four decades of Soviet-era achievement from 1952.
Japan notched up the 100th gold medal of its Summer Olympics history with judoka Tadahiro Nomura's record third title, and China were 15 golds away from the 100 milestone.
The Chinese led the early medals tables with five golds and hoped for a big haul on Monday in the synchronised diving.
Australia's Sara Carrigan upstaged the favourites to win the women's Olympic cycling road race while Dutch defending champion Leontien Zijlaard-van Moorsel crashed out with two laps to go.
In a fresh doping case, Slovak shot putter Milan Haborak tested positive for a banned substance and left the Olympics, the Slovak news agency SITA reported.
"I really am sorry because I was really looking forward to competing. I trained long and hard. But I do not know that I took something that is banned," SITA quoted Haborak as saying.
Sidelined judoka Miresmaeili was quoted by Iran's official news agency IRNA as saying he "refused to face my Israeli rival in sympathy with the oppressed Palestinian people".
But shunned Israeli opponent Ehud Vaks told Israeli Army radio he felt sure Mirasmaeili had no choice, and in Tehran a spokeswoman for Iran's Olympic committee said he was told to pull out, in line with national policy toward Israel.
Iran's President Mohammad Khatami also left no doubt about the reasons behind the pullout, saying Miresmaeili's action should be "recorded in the histoy of Iranian glories".
Among those lamenting the blight was spokesman Yaron Michaeli, who said the Israeli team "are sorry for the athlete because he is very good and could have won a gold medal".
Talks on what Olympic judo would do were due on Monday.