LONDON - World champions Japan advanced into the quarter-finals of the Olympic women's football tournament after a goalless draw with South Africa in Cardiff on Tuesday.

Striker Kozue Ando and midfielder Asuna Tanaka wasted the best chances for Japan, who are now set for a last eight clash with Great Britain should the hosts beat Brazil later Tuesday.

For South Africa, the draw was their first point of the Games after they'd twice been well-beaten in their previous Group F matches.

Japan were on top from the start and Ando had two early chances as her shot was smothered by Thokozile Mndaweni, before heading wide following a cross by Karina Maruyama.

However, South Africa rallied and Portia Modise went close to opening the scoring with a long-range shot that skimmed over the crossbar.

Mana Ibwabuchi was off target early in the second half and Ando struck an effort across th face of the goal after more good approach play by Maruyama.

South Africa midfielder Gabisile Hlumbane was carried off on a stretcher after colliding with Mndaweni as the keeper came for a cross.

But South Africa continued to frustrate Japan, Tanaka headed over under pressure at the far post before Janine van Wyk's excellent block kept the match goalless.

(AFP)