US Open Tennis 2013 Schedule: Can't-Miss Matchups for Day 8

The top seeds have been challenged at the U.S. Open, but most are still alive in the tournament. This allows there to be a truly exciting Round 4 at the last Grand Slam event of the year.

With so many experienced players on tour, the sport is as deep as it has ever been. All of a sudden, there are no guarantees that stars like Novak Djokovic or Andy Murray will reach the semifinals in every single tournament.

This possibility for upsets makes the early rounds even better, as you have to make sure not to miss your favorite player before he or she is eliminated.

These matches taking place on Day 8 feature either even matchups or a decent chance of an upset, making them must-see TV.

You can find a full look at the daily schedule at USOpen.org. 

Roger Federer vs. Tommy Robredo

After reaching the quarterfinals of 36 Grand Slams in a row, Roger Federer lost in the second round at Wimbledon. All of a sudden, winning this match is far from a guarantee, especially for a player that has fallen to No. 7 in the world rankings. 

Federer cruised in his third-round win over Adrian Mannarino, but Tommy Robredo represents the first real challenge of the tournament. The 31-year-old veteran has two tournament titles this year, which is actually more than the Swiss star has all season.

Robredo also has a quality serve that could give Federer trouble in the return game. Every set in this match is likely to be a battle, and we could see the former No. 1 go down if he cannot get some breaks.

Rafael Nadal vs. Philipp Kohlschreiber

At this point, it is hard to imagine anyone on tour beating Rafael Nadal. The clay-court master has figured out how to succeed on hard courts as well, totaling an amazing 18-0 record on the surface this year.

The Spanish player is also coming in with back-to-back wins at Masters 1000 events in Montreal and Cincinnati and is easily the favorite to win the U.S. Open.

However, one thing that could help Philipp Kohlschreiber in this match is his serving consistency. Most players have a huge drop in success rate from their first serve to their second serve, but the German ranks second in the world at winning 57 percent of his second serves.

Nadal usually uses that time to his advantage, and he might struggle to win as many breaks as he is used to, slowing him down in the match.

Victoria Azarenka vs. Ana Ivanovic

After two easy matches to start the U.S. Open, Victoria Azarenka struggled in her third match against Alize Cornet. She lost the first set on a tiebreak and then needed to come from behind by winning two sets in a row to survive.

At least Cornet is a seeded player with plenty of experience. Ana Ivanovic barely escaped her third-round match as well, although this was against unseeded Christina McHale. In that match, Ivanovic had 51 unforced errors and five double faults.

Both players are capable of better than they displayed in the previous round, but it will be up to them to figure out what went wrong. Whoever is able to come through with a cleaner game with fewer mistakes will advance to the quarterfinals in the women's draw.

Richard Gasquet vs. Milos Raonic

There are no upset alerts in this match; this is simply a great battle between two evenly matched competitors.

Milos Raonic is a player that fans always want to watch due to his incredible serve. He is third in the world with 509 total aces and leads everyone with an 80 percent success rate on his first serve.

Meanwhile, Richard Gasquet is one of the better defensive players in the sport, and he has beaten players of this quality before. His ability to get to tough shots will help him against even the biggest winners by Raonic.

This is truly a matchup of strength against strength, and it will be interesting to see who can survive to reach the quarterfinals.

Note: Unless otherwise noted, all stats courtesy of ATPWorldTour.com.

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