Novak Djokovic of Serbia
Novak Djokovic of Serbia returns a shot to Andreas Haider-Maurer of Austria during their second round match at the U.S. Open Championships tennis tournament in New York, September 2, 2015. Reuters/Carlo Allegri

Serbia's Novak Djokovic admitted that he struggled with the powerful serves of his opponent, but nonetheless, came away with a straight set victory, 6-4 6-1 6-2 against Andreas Haider-Maurer of Austria in the second round of the 2015 US Open.

“I think he had an average serve of 130 miles per hour, so came out firing from that shot in his game,” Djokovic said in the post-match interview referring to the Austrian’s potent serves. “Never played him on hard courts. We played only once earlier this year on clay courts, but it's completely different.”

The match in Flushing Meadows, New York lasted just about one hour and a half as Djokovic broke Haider-Maurer’s serves in 5 of 10 break opportunities.

The Austrian averaged 126 mph on his first serves but he also had 33 unforced errors and Djokovic took full advantage especially in the last two sets. Djokovic also had the edge in total winners for the match, 27-7.

Djokovic also added after the match that he is aggressively trying to go hard at the net in some moments of the match, stating the influence of his coach Boris Becker, who was a known efficient net player during his prime.

“[Becker] does encourage me to, you know, step in, try to use the opportunities when I open up the court to come in. Obviously it's not as natural for me as it was for him or some other players, but I'm trying. I'm obviously looking to develop my game and better it every week,” Djokovic, who won 14 of 23 net points attempts in his second round match, added in the tournament's official website.

The Serbian advanced to the next round where he’ll face Italian Andreas Seppi, a winner over Russia’s Teymuraz Gabashvili, 3-6 6-3 7-6 (3) 6-1 in his own second round match-up.