DUBAI: Defending champion Novak Djokovic scored an easy 6-3, 6-3 first round win over Uzbekistan’s Denis Istomin in the Dubai Duty Free Tennis Championships on Tuesday.

Earlier, Juan Martin Del Potro was forced to retire with a left wrist injury.

The No.2 seed had been suffering with the injury before he arrived in Dubai, and he sought medical advice in the United States following his opening round loss at the Australian Open last month.

Although he broke to lead 2-0, Del Potro immediately dropped his own serve in the next game and after failing to convert three set points on his opponent’s serve at 6-5 he conceded the tiebreak 7-3.

“My wrist is hurting a lot and it was really tough to play today and I tried everything, but it’s very difficult play like in these conditions, you know, playing slices or I cannot be the player what I would like to be,” said Del Potro.

“It’s hurting all the time, it’s sometimes less and sometimes little more. But it’s hurting, and I have been in contact with my doctor all the time. He’s trying to keep me motivated to keep playing, but I know what it’s my limit playing on court. Today was enough. I have been doing a big effort to play this tournament, and it was not enough to play what I like to play.”

Devvarman realized after a few games that Del Potro was uncomfortable and exploited the situation.

“After starting the match, I realized that he wasn’t very comfortable hitting backhands obviously, and I tried to make him hit as many as I could, and he wasn’t really hitting over it, so I knew that he wasn’t happy,” said Devvarman. “I just tried to fight hard and tried my best to make things tough for him, make things easier for me.

“Obviously it’s unfortunate, you know, especially for a guy like him. I think he’s been playing really good tennis to be in the top 5, and I wish him nothing but the best and a good recovery.”

Earlier, Tomas Berdych claimed his 13th victory in his last 14 matches by beating qualifier Marius Copil 6-3, 6-4.

There was a 6-3, 6-4 win for sixth seed Mikhail Youzhny over Michal Przysiezny, Lukas Rosol beat Daniel Brands 7-6, 6-4 to set up a clash with eighth seed Dmitry Tursunov, and Tunisian wild card Malek Jaziri saved five match points to claim an upset 0-6, 6-4, 7-6 victory over Igor Sijsling.