It was a straight set win for Novak Djokovic on Thursday night, but the victory was far from routine. In a match much closer than a score of 6-2, 7-6(2), 6-4 would suggest, Djokovic moved one step closer to defending his US Open title by beating Juan Martin Del Potro in a little over three hours.

The world no. 2 came out strong and looked to be cruising. The first set was over before you could blink it seemed, and you could tell the crowd was a bit disappointed. After all, Del Potro is the guy that sent fan favorite Andy Roddick into retirement on Wednesday. That had to have given him some kind of momentum right? Well maybe that win against Roddick popped into his mind all of a sudden, because he came alive in the second. We were now seeing the Del Potro from 2009, the year he won the New York slam. The second set alone was 82 minutes long, and consisted of a 17 minute game, with eight deuces, at 6-5 to force a tiebreaker. But whatever momentum was swinging in his direction somehow diminished and Djokovic won the tiebreak fairly easily with a score of 7-2. And from there on out it seemed like the Argentinian ran out of steam.

It’s really no surprise that Novak Djokovic won the matchup against Juan Martin Del Potro. Let’s be honest, we all expected him to be playing for the trophy come Sunday. But we all assumed that Roger Federer would be playing alongside him. With the number one player in the world out in the round of 16, the big question remains: who will be Novak’s opponent come Sunday? And regardless of who it is, is Djokovic a shoe in to win the fourth and final grand slam of the year? If you ask me, the only player that can really come close to matching Djokovic is Andy Murray. But he’s struggled in his last round or two. And his epic five set win over Cilic most assuredly took a lot out of him. Will he be able to muster up enough energy to be able to keep up with the Serbian? I wouldn’t be so sure.