Like Andrea Petkovic, Petra Kvitova of the Czech Republic is among the rising stars in Women's tennis. On Monday, she will try to follow the footsteps of her young German rival, who crushed Maria Sharapova in the round of 16, in order to reach the Australian Open quarterfinals.
On the men's side, Rafael Nadal might face his first major test of the tournament when he takes on Croatia's Marin Cilic.
Some might remember the 20-year-old Czech player from Wimbledon last year, when she reached the semifinals against Serena Williams.
Yet Kvitova remains fragile. But when she's in full flight, she's overwhelming, as proved her last match, when she beat local favorite Sam Stosur. Her huge first serve and her flat shots played early make her a really tough player to handle.
Kvitova is now on an eight match winning streak. By qualifying for the last eight, she would likely deliver the Czech her top 20 debut and although seeded lower than Pennetta, she probably goes into the match as favorite (as well as recent momentum, she beat the Italian last time they met, on hard courts at Beijing in October).
That said, the former world No. 12 dug deep to overcome Shahar Peer in the third round, which was exactly the sort of win the former top 10 player needs to set her stocks back in the right direction. The world No. 28 boasts the more explosive arsenal and if she hits her mark, it may be hard for Pennetta to rally.
Not a lot has been said about world No. 2 Vera Zvonareva, but she remains a contender for her first major title.
On the other side of the net, making her round of 16 debut at a major just shy of her 28th birthday, Benesova is 3-26 in her career against top 10 opponents. But the good news is that one of those big wins was against the Russian.
Granted, that was nearly six years ago on clay at Charleston, but every little thing helps.
Indeed, while the last Wimbledon and US Open finalist conceded just three games when they met here in the second round last year, this pair has otherwise played tight matches. The world No.2 will know that No.60 isn't a true reflection of the Czech lefty's skill and experience.
However, one reason Zvonareva has climbed so spectacularly over the past year is that she has mostly excised big shocks from her record: since the start of 2010, she is 17-3 against players ranked outside the top 50. That should add up to a bit too much of everything for Benesova on Monday.
Experience and a bad match is what the three-time US Open champion might need to win this title.
On Saturday, Clijsters defeated France's Alizé Cornet by making 25 unforced errors.
On that occasion she had to wait for the proper moments to make the difference. It was a bad day at the office, which is all champions need in order to find their best tennis.
Also, props to Makarova, who has built on her upset of Ana Ivanovic in fine style, last round edging her more celebrated countrywoman Nadia Petrova 8-6 in the third set. The way the lefty has played this week—and indeed, the way she played at Eastbourne last year, when as a qualifier she beat five top 20 players in a row to clinch the title—begs the question: why isn't she higher in the rankings?
A first Grand Slam fourth round will no doubt help in that respect, but going further is a lot to ask.
Another ominous stat about the Belgian: only once in her career has she lost to an opponent ranked outside the top 10 in a Grand Slam fourth round or later (Zvonareva at Wimbledon last year). Makarova won't give an inch, but she probably should also pray for a lapse in concentration by her opponent.
Correction to those who thought the world No. 1 had a winning record against each ATP Players.
I would have made the same mistake, but Croatia's Marin Cilic is one of just four active players who have a winning head to head record against Nadal. Nikolay Davydenko leads Nadal 6-4, while both Chris Guccione and Nicolas Mahut lead the No. 1 seed 1-0.
The only time Nadal and Cilic have previously met was at 2009 Beijing Open, which the Bosnia-Herzegovina native won 6-1, 6-3. Can the Croatian stop Nadal from winning his fourth consecutive Grand Slam title?
The last time the top seed failed to reach the quarterfinals at a Grand Slam event was when Nadal fell in the round of 16 to Robin Söderling at 2009 Roland Garros.
This is the only time that Nadal has failed to reach the quarterfinals or better at one of the majors in the last three years.
Elsewhere, Cilic needed close to five hours to beat Isner in the previous round, which will be a factor if today's match goes further than three sets.
In contrast, Nadal needed less than five hours in winning his first three matches of the tournament.
The 22-year-old will have to serve the same way he did against the tall American, and even better for three consecutive sets and hope that the Spaniard has a let down during the match.
Warning! Andy Murray has yet to drop a set in 2011! Bad news for the Austrian, who will need to play better than he did against the Scot in their four previous meetings.
The fifth seed remains undefeated in singles matches so far this year, as he enters his round of 16 match here on a six match winning streak.
Of course, the Austrian is bidding to reach the quarterfinals here for the first time in his career.
The 11th seed is also projected to enter the top 10 regardless of this match, and record a career-high ranking when the new rankings are published.
Elsewhere, Melzer might want to find some inspiration from last year's French Open, when he broke through to his first Grand Slam semifinal at 2010 Roland Garros—his best Grand Slam result to date. On this occasion, he upset Novak Djokovic in the quarterfinals for his first ever comeback from 0-2 down, before losing to Rafael Nadal in the semifinals.
Melzer has a solid game, but the surface favors Murray, who will be the favorite due to his serve, which is much more effective than the one of the Austrian.