Japan had to overcome an early scare before sealing their progress 2-0 at the Millennium Stadium.
The Samba Queens desperately sought an equaliser after the interval but were caught out by a rapid counter-attack which allowed Shinobu Ohno to seal Japan's win and set up a semi-final meeting with France.
The French progressed in their first-ever appearance in the Olympic women's Football tournament with a hard-fought 2-1 win over Sweden at Hampden Park.
Nilla Fischer had given the Swedes the lead after 17 minutes as Marie Hammarstrom's corner deflected fortuitously off her shoulder into the corner of the net, but France were level 11 minutes later when Laura Georges headed home at the back post from another corner.
France claimed the lead thanks to a Wendie Renard goal seven minutes before half-time, but Bruno Bini's side were grateful to goalkeeper Sarah Bouhaddi as she produced a brilliant one-handed save from Fischer to ensure the game did not go to extra-time.
Abby Wambach's fourth goal of the tournament helped to fire the USA into the last four as New Zealand's hopes were dashed by a 2-0 scoreline.
The 32-year-old striker turned home Alex Morgan's 27th-minute cross to give her side the advantage in a game the USA controlled but failed to put beyond doubt until substitute Sydney Leroux made sure close to the end.
Last year's beaten World Cup finalists won with something to spare and will head into their semi-final at Old Trafford on Monday with hopes of a third successive gold medal very much intact.
The same can not be said for Host Nation Great Britain, however, after they were sent out of the competition 2-0 at the hands of Canada.
Jonelle Filigno and Christine Sinclair got the first-half goals to send the Canadians into the semi-finals, but in truth it should have been more.