Novak Djokovic meets Tommy Haas on Monday in the fourth round of the 2013 Wimbledon Championships.  The match is slated for 1 p.m. ET.  Watch the live stream HERE.

World No. 1 Djokovic hasn't dropped a set thus far at Wimbledon.  He's defeated Florian Mayer (6-3, 7-5, 6-4), Bobby Reynolds (7-6, 6-3, 6-1) and, most recently, Jeremy Chardy (6-3, 6-2, 6-2).  The early exits of Rafael Nadal and Roger Federer haven't only improved his chances of capturing his second Wimbledon title, it's also made him the only remaining champion in the draw, according to TennisEarth. 

Opposite of Djokovic on Monday is Haas.  The German is the oldest player left in the draw, the Guardian reports.  Yet, at the age of 35, Haas has looked untouched by Father Time.  He's dropped only one set -- in the third round against Feliciano Lopez -- so far at Wimbledon. 

Haas credited his ability to still compete at an elite level to the advances in health and nutrition.

"A lot of people are smarter over the years of what to do in order to get in better shape," he told reporters.  "You have a good team around you.  You can do a lot of stuff also nutrition-wise.  There's a lot of things."

The No. 3 World-ranked player beat Djokovic in straight sets when they met in March at the Sony Open in Miami.  Though Djokovic beat Haas on clay during the 2013 French Open, he is wary about facing the German on grass.

"It's going to be a big challenge for both of us," Djokovic told reporters.  "I think it's his most preferred surface.  He loves playing on grass.  He had a few great wins lately.  He beat Roger in the finals of Halle last year.  He played again really well this season on grass.  He's 35 years old, and he's been playing very close to the best tennis of his life, in my opinion."

In a tournament filled with upsets, Haas has the opportunity to give Wimbledon yet another.