Great Britain's women maintained their unbeaten hockey record in Rio with a 2-0 victory over Japan.
Miyuki Nakagawa volleyed Lily Owsley's cross into her own net to put the Britons ahead by half-time.
Helen Richardson-Walsh swept in a second but it was disallowed after the ball hit a player in the circle.
However a superb finish from Nicola White in the fourth quarter to knock home a rebounded penalty ensured the quarter-finalists ended on a high.
A late block from goalkeeper Maddie Hinch denied Japan a late consolation strike.
GB, who have already qualified for the last eight, will play the United States, who are also unbeaten in the tournament, in a pool match on Friday.
Great Britain coach Danny Kerry said: "I don't think anyone will be happy with the team performance. However, we've kept a clean sheet, won the game and not played that well.
"Looking at the big picture, we've won four group games and we're definitely in the top two so if you'd offered us that we'd have taken it every day."
Elsewhere in the pools
Emily Smith scored the only goal as Australia beat Argentina 1-0 in Pool B, while Kathleen Bam's double ensured a 3-0 victory for the United States over India.
Spain registered their first win of the tournament as they beat Germany 2-1 in Pool A.
And in the men's
Belgium beat Spain 3-1 to go three points clear at the top of Pool A and push Great Britain down to fifth place.
Shane O'Donoghue scored twice in Ireland's 4-2 victory over Canada in Pool B, while a last minute goal from Mathias Muller earned Germany a 4-4 draw with Argentina.
Pool leaders the Netherlands extended their advantage over Germany with a 2-1 win over India.