When James Blake describes his task of making inroads in this year's Australian Open as a "challenge," you are inclined to sit up and take notice.

After all, the world No. 10's idea of a challenge is presumably somewhat different than most people's, having emerged through a series of potentially crippling setbacks to put together a successful tennis career.

As a child, Blake was forced to wear a back brace for 18 hours a day after developing severe scoliosis. Five years ago, he was the victim of a freak tennis accident, slipping on a clay court and breaking his neck after colliding with a net post. Later the same year, half of Blake's face became paralyzed and his sight was affected by an extreme case of shingles.

Blake refused to be bowed, however, and at nearly 30 years old he is playing some of the best and most intelligent tennis of his career. Three straight wins with a loss of only one set has put him into the round of 16 at the Australian Open, and within reach of his best-ever

The big names continue to surge at the Australian Open, setting up a huge second week in Melbourne.

On the men's side, the Big Four remain in position in our latest edition of the Yahoo! Sports power rankings. But behind them, the pack is bunched together and jostling for position.

Fernando Verdasco was the biggest mover, after conceding just four games for the third match in a row as he demolished Radek Stepanek.

Serena Williams has endured some shaky moments, giving confidence to women's title hopefuls Jelena Jankovic, Elena Dementieva and Dinara Safina. But Williams' draw makes her an overwhelming favorite to reach at least the semis, where Dementieva could lie in wait.

Men

1. (1) Andy Murray: Talented Brit marches on but has a tough route to the semis. Round 4: vs. Fernando Verdasco.

2. (2) Rafael Nadal: Cranking up the power as he seeks his first Melbourne final. Round 4: vs. Fernando Gonzalez.

3. (3) Roger Federer: Smoothness and consistency are back after a difficult 2008. Round

Marat Safin arrived at the Australian Open bloodied and bruised from a fight in Moscow. He left it with scars of a more emotional kind.

Safin is the latest victim of the newly revitalized Roger Federer juggernaut, as proof continues to mount that the former world No. 1 is getting back to his imperious best.

Federer swept Safin aside in straight sets, cutting down his old rival and disappointing the neutrals desperate to see a repeat of their epic 2005 semifinal, won by Safin 9-7 in the fifth set.

After a 2008 that saw his previously invincible form dip and push him down to No. 2 in the rankings, Federer is sizing up a return to the top this year.

Signs are that he is getting closer. The metronomic consistency that marked his rise to the summit of men's tennis is back, with few unforced errors and a stellar service game.

The energy and focus which seemed to be missing during the middle of last year are in place once more, and Federer has breezed through his first three matches in

With a handful of exceptions, the Australian Open so far is not living up to its reputation as the most unpredictable of the Grand Slams.

In the men's field, 24 of the 32 seeds have reached Round 3, including each of the top eight.

Our men's power rankings were shuffled but no one dropped out – although a series of players including Gael Monfils, James Blake, Fernando Verdasco, David Ferrer and a couple of others are knocking on the door.

The women's list was turned on its head by Venus Williams' shocking exit after losing to Spanish youngster Carla Suarez Navarro. Williams looked poised to hit the top spot after younger sister Serena Williams endured a shaky second round. Instead, she is out of the tournament and out of the power rankings after squandering a big third-set lead.

Check back here after Round 3 for the next edition of the Yahoo! Sports Australian Open power rankings.

Men

1. (1) Andy Murray: beat Marcel Granollers 6-4, 6-2, 6-2; faces Jurgen Melzer in Round 3. Hard-court

The bulging biceps are hidden now, with a more traditional sleeved shirt replacing the trademark vest top, but still there is no doubting the physical toughness of Rafael Nadal.

The world No. 1 ended 2008 with his glorious and spectacular season tinged slightly by concerns over his health. At the U.S. Open, Nadal looked spent in his semifinal defeat. He was forced to miss the season-ending championships and the Davis Cup final to recover from a knee injury. The Spaniard’s remarkable summer, which culminated with a gold medal at the Olympic Games in Beijing, can be held responsible for the dip in energy reserves in New York.

But there is no question that he is at full strength again now. Nadal’s second-round opponent, Roko Karanusic, had no answer and was swept aside 6-2, 6-3, 6-2. Different shirt, same old Nadal.

With that hulking frame and pounding ground strokes that squeeze the sap out of opponents’ legs, physicality defines Nadal’s game. If the 22-year-old’s gifts carry him to many

Soccer-style chanting from the stands in tennis is usually reserved for the Davis Cup. But increasingly, the Australian Open -- the so-called Happy Slam -- is being marred by the threat of crowd trouble.

Wednesday saw insults traded between Serbian and Croatian supporters during a second-round men’s match won by Marin Cilic, a Croat, against Janko Tipsarevic, a Serb.

A strong police and security presence helped to ensure there was no violence at courtside, although arrests were made at a nearby bar as tempers flared afterward.

There is a fierce rivalry between ex-pats and descendants of the countries which used to form part of Yugoslavia. Australia has a significant population of Serbs and Croats, and there were ugly incidents between fans of those countries at Melbourne Park two years ago.

Tipsarevic specifically asked for his match with Cilic to be moved to a show court so that aggravation would not spill over.

Though there were no flying fists and decorum between points

It took just a few moments after Venus Williams slid into her chair in the Melbourne Park media theater for the questions to start flooding in about Barack Obama.

After sister Serena Williams had earlier waxed emotional about the incoming president, reporters were determined to elicit the thoughts of the elder Williams.

However, they quickly found Venus’ current focus remains on one thing, an inauguration of her own Down Under.

As Jehovah’s Witnesses, the Williams sisters are essentially apolitical, refraining from voting and discouraged by their religion from following secular politics.

Yet while Serena could not help but get caught up in the excitement of Obama’s big day, Venus’ thoughts were trained simply on winning the Australian Open for the first time.

Venus Williams has never won at Melbourne Park, yet shares tournament favoritism with her three-time champion sister.

A 6-3, 6-3 victory against Angelique Kerber of Germany was the right kind of start, although Kerber did put up a

Rafael Nadal’s swashbuckling start to his Grand Slam year pushed him up a spot in our Australian Open power rankings and made a powerful signal of intent.

The Spaniard has never made it past the semifinal in Melbourne but looked hungry and motivated as he swatted aside Belgium’s Christophe Rochus.

Frenchman Jo-Wilfried Tsonga and Gilles Simon both moved up after convincing wins in the searing heat Down Under and look poised for deep runs into the tournament.

There were still no massive upsets among the elite on the women’s side, yet Elena Dementieva moved down two spots due to her shaky performance in the opening round.

Check back for our next power rankings at the conclusion of the second round and share your thoughts below.

Men's

1. (1) Andy Murray: Easy start, beating Andrei Pavel 6-2, 3-1 ret.

2. (3) Rafael Nadal: Looked awesome in 6-0, 6-2, 6-2 destruction of Christophe Rochus

3. (2) Roger Federer: Faces Evgeny Korolev in round two

4. (4) Novak Djokovic: Faces Jeremy Chardy in