Matches to watch, day 7

We're into the first weekend, and the majority of the players are gone. Only 32 players are left out of the 256 which started the tournament, and the match-ups are starting to get tighter and tighter.

Yesterday may have been the most disappointing first friday of a major in recent history. In sharp contrast to the unbelievable weekend two years ago, which featured Federer getting pushed to five sets, Blake winning his first five-setter, and Hewitt and Baghdatis playing until nearly five in the morning, yesterday was characterized mostly by retirements and blowouts.

The only really competitive match was between JW Tsonga and Tommy Haas, and it almost made up for the dearth of good play in the other matches yesterday. Tsonga is looking strong, and should have little trouble with a hobbled Almagro. The Tsonga-Djokovic quarterfinal match (if it comes to pass) will be thrilling.

But looking ahead to today's matches, almost every one has the possibility (at least slightly) of an upset.

John Isner v. Andy Murray - These two have never played, and while Murray has not been challenged yet this tournament, that may actually work to his disadvantage. Isner has been on fire, hitting bombs on his serve, cracking winners from the back of the court of both wings, and pulling clutch volleys at net. Murray has such a great return that it may neutralize his best weapon, but John is more than just a big serve these days. And Isner is the kind of power player and big hitter that has troubled Murray in past grand slams.

Ivo Karlovic v. Rafael Nadal - The same could be said for this match, which features a massive server and one of the best returners in the game. If Karlovic has a good serving day and the conditions suit his game, it will be tough for Nadal to get involved. Dr. Ivo can pull off a huge upset on any given day. Remember, he ousted defending champ Lleyton Hewitt in the first round of Wimbledon in 2003.

Justine Henin v. Yanina Wickmayer - It's the battle of the Belgians! Just, not the one that everyone expected. Wickmayer is making the most of her suspended suspension, but this will be a tough ask, tonight. Justine, on the other hand, is so out of match practice that one has to expect she'll run out of gas eventually. She absolutely escaped against her opponent in the last round, so we'll see if she bounces back tonight or is even more drained than she was before.

Fernando Gonzalez v. Andy Roddick - Here's popcorn match of the night. Expect big hitting from both guys, as I don't know if Roddick will be able to grind as much as he did in his previous matches against something that hits as big as Gonzo. With Cilic's mental strength uncertain and Del Potro's injury seeming to continue to bother him, the winner of this match is almost certainly into the semis, where they will likely face an exhausted Nadal or Murray, whichever one comes out on top. This is an important match for both of these players.

Marin Cilic v. Juan Martin Del Potro - The two big guys are meeting at this year's Aussie Open, again. They played here last year, as well as at the U.S. Open. Their matches have been tight, but so far, DelPo has come out on top. Today, it's up for grabs. Cilic has shown flashes of brilliance as well as some stretches of lesser play, but so has the U.S. Open champion.

There are also a pair of Russians quietly moving through the draw who nobody seems to be paying attention to, yet. Safina plays Kirilenko, who upset Sharapova, and Kuznetsova plays Petrova, fresh off her win over Clijsters. Both of these players could announce that they're here to win the tournament, if they continue their levels of play tonight.