Reigning world champions the United States have lost 10-9 to Hungary at Tokyo to slump to their first defeat at an Olympics since 2008, ending the Games' longest winning streak in women's water polo at 12 matches.
Gunning for their third straight gold in Tokyo, the US women last failed to win a match at the Olympics in the group stages of London 2012, when they drew with Spain in their third game.
Their previous defeat on sport's biggest stage was 13 years ago in the final of the 2008 Beijing Olympics, where they finished runners-up to the Netherlands.
Rebecca Parkes, who top-scored for the Hungarians with three goals, fired home the winner with 45 seconds left in the final quarter, while their goalkeeper Alda Magyari made 11 saves.
Madeline Musselman scored three for the US, whose captain Maggie Steffens also found the net, despite playing with a broken nose sustained in their nervy win over China on Monday.
"We were a little rushed, a little anxious, but I'm certainly proud of the way we kind of just kept battling," US coach Adam Krikorian said.
"We need to settle down and find our legs and a little bit more patience and composure.
"We wish we'd finished off the game, but we'll learn from this and move on."
The defeat was not enough to knock the US off top spot in Group B and they will still qualify for the quarter-finals if they win their final group game against the Russian Olympic Committee (ROC) team on Friday.
The 10 women's teams in Tokyo are split into two groups, with the top four on each side of the draw advancing to the knockout rounds.
The US will progress even without beating ROC if other results in Group B go their way.
Meanwhile, European champions Spain were beaten 14-13 by the Netherlands in another big upset thanks to Simone van de Kraats' six goals as the Dutch team earned their first win of the tournament.
Australian Associated Press
