Power Rankings (Jan. 26): Quarterfinal breakdown

Despite Andy Murray's exit at the hands of brilliant Spaniard Fernando Verdasco, the men's quarterfinals are still loaded with talent.

Murray was the only top-eight seed who failed to reach the quarters and the tournament is building toward a thrilling crescendo.

Rafael Nadal remains atop the Yahoo! Sports Australian Open power rankings, having hardly been stretched on his way to the last eight.

On the women's side, Serena Williams was fortunate to escape her fourth-round clash with Victoria Azarenka – her 19-year-old opponent took ill after winning the first set.

However, Williams is still very much the woman to beat and has high hopes of adding yet another Grand Slam title to her collection.

Men

1. (2) Rafael Nadal: Twelve straight sets won without even being taken to a tiebreak. QF: vs. Gilles Simon.

2. (3) Roger Federer: Survived a scare but is still a huge title threat. QF: vs. Juan Martin Del Potro.

3. (5) Fernando Verdasco: Big serve is finally matching devastating ground game. QF: vs. Jo-Wilfried Tsonga.

4. (4) Novak Djokovic: Defending champ will need to up his levels to regain crown. QF: vs. Andy Roddick.

5. (-) Jo-Wilfried Tsonga: Last year's finalist is lurking dangerously again. QF: vs. Fernando Verdasco.

6. (7) Juan Martin Del Potro: Big chance to show he belongs with the elite. QF: vs. Roger Federer.

7. (6) Gilles Simon – Through to a Slam quarterfinal for the first time. QF: vs. Rafael Nadal.

8. (8) Andy Roddick: Aiming to reach his first Slam semi in two years. QF: vs. Novak Djokovic.

Women

1. (1) Serena Williams: Edging closer to a fourth Australian Open title. QF: vs. Svetlana Kuznetsova.

2. (3) Elena Dementieva: Biggest remaining threat to a Serena Williams victory. QF: vs. Carla Suarez Navarro.

3. (4) Dinara Safina: Will love her chances of reaching the final after seeds tumbled. QF: vs. Jelena Dokic.

4. (6) Vera Zvonareva: Calmly working her way through the draw and a real contender. QF: vs. Marion Bartoli.

5. (5) Jelena Dokic: Aussie star wants to keep the fairytale run alive. QF: vs. Dinara Safina.

6. (7) Carla Suarez Navarro: Conqueror of Venus Williams keeps marching on. QF: vs. Elena Dementieva.

7. (-) Marion Bartoli: Best Slam performance since reaching the 2007 Wimbledon final. QF: vs. Vera Zvonareva.

8. (-) Svetlana Kuznetsova: Out of form and fortunate to have avoided elimination. QF: vs. Serena Williams.