Defending champions the Netherlands moved into the semi-finals of the Olympic women's hockey tournament on Saturday by defeating South Korea 3-2 for their fourth successive victory.
The Dutch were made to work hard by South Korea before taking their tally to 12 points from four matches to head Pool A.
In the same group, China came back into the chase for semi-finals with a 2-1 victory that stopped Great Britain's winning spree.
Britain remain in second place with nine points from four games, while China boosted their tally to seven points.
The hosts' semi-final hopes now hinge on their last game against the Dutch on Monday, while earlier that day China will play the group's bottom-placed team, Japan.
The situation in Pool B did not become much clearer despite wins for world champions Argentina, Australia and New Zealand.
The day finished with those three teams locked on nine points and Germany who have still to play New Zealand, three points adrift after losing 3-1 to Argentina.
However, Argentina -- who play Australia on Monday -- have comfortably the best goal difference of the top three.
South Korea's Cheon Seul Ki converted two penalty corners to trouble the Dutch, who got all their goals in open play.
Cheon opened the scoring by sending a drag-flick into the top corner in the fifth minute, but the Dutch were back on level terms in the 10th minute on Kelly Jonker's reverse deflection of captain Maartje Paumen's shot.
Ellen Hogg open field strike four minutes later gave Netherlands the lead and Carlien Dirkse van den Heuvel made it 3-1 one minute after half-time.
Cheon pulled another goal back from a penalty corner in the 64th minute
Max Caldas, coach of the Netherlands, said: "I'm obviously happy to be in the semi-finals, but I want to see more goals."
Kate Walsh, Britain's captain, returned to play after surgery to fix a fractured jaw sustained in their opening game of this tournament.
But it was China who seized control of the game through penalty corner conversions by Fu Baorong in the 41st minute and Zhao Yudiao six minutes later.
Crista Cullen pulled a goal back for Britain on a penalty corner one minute from full-time.
"We're disappointed with our performance," said Walsh. "We can play better that that."
As for her injury, Walsh added: "I put my mouth in some silly positions. It was my own fault.
Australia rode on Jade Close's early field goal to beat South Africa 1-0 in Pool B and set the target in the group with nine points from four matches.
Argentina maintained their recent supremacy over Germany with a 3-1 win in the day's last game.
Early goals by Sofia Maccari and captain Luciana Aymar, set the tone for Argentina's third win out of four games.
German defender Nina Hasselmann did score late on but Rocio Sanchez Moccia immediately replied.
New Zealand's penalty corner drills saw them through in a 3-2 win over the United States who were level at 2-2 until the last six minutes.
Kiwi captain Kayla Sharland, Gemma Flynn and Clarissa Eshuis scored for the Black Sticks, while Katie O'Donnell and Claire Laubach were on target for the United Staes.
Mark Hager, the New Zealand coach, said: "The US made it bloody hard for us. We could still be playing in the semifinals or for the 7th/8th place.
"It still depends on our next match against Germany on Monday."