Novak Djokovic is serious in his bid to win his second Grand Slam title this season. After a masterful 6-0, 6-3, 6-2 victory over Joao Sousa in the third round of the 2013 U.S. Open, the Serbian is proving so far why he is seeded number one at Flushing Meadows.

It was easy work for the 33-year-old as he finished the match in just under two hours. Djokovic’s first serve was on target as he hit 30-of-38 or 79 per cent. He hit 34 winners as well compared to Sousa who hit just 10.

“I've been working on basically every element in my game, so hopefully I can serve a little bit more efficiently and get some more free points on that in the next matches," said the Serbian a postgame interview.

The win marks Djokovic’s third straight-sets win in this tournament. The Serbian defeated Lithuanian Ricardas Berankis, 6-1, 6-2, 6-2 in the opening round and beat German Benjamin Becker, 7-6, 6-2, 6-2 in the second round.

In 2012, Djokovic had a similar excellent start in the U.S. Open but fell to Andy Murray in the championship match in a 5-set classic, 6-7, 5-7, 6-2, 6-3, 2-6. The two are set to meet in the semifinals if both top seeds manage to avoid an upset in the next two rounds.

He will meet Marcel Granollers from Spain in the fourth round.

The 86th ranked Sousa was appearing in his first-ever U.S. Open stint and his first-ever third round Grand Slam match. The Portuguese upset 25th seed Gregor Dimitrov, 3-6, 6-3, 6-4, 5-7, 6-2 in the first round earlier this week.

Djokovic won the Australian Open title earlier this year but came up short both at Roland Garros and Wimbledon.