DUBAI, United Arab Emirates -- Novak Djokovic opened the defence of his Dubai Championships title with a straight sets victory over Denis Istomin, while second-seeded Juan Martin del Potro had to retire from his first-round match on Tuesday. Top-seeded Djokovic, who is making only his second appearance this year after reaching the quarterfinals of the Australian Open, was a 6-3, 6-3 winner over 54th-ranked Istomin of Uzbekistan. "It wasnt as easy as the scoreline indicates," said Djokovic, who has won in Dubai on four occasions. "I needed to work for my games. "Having not played for more than four, five weeks, an official match, obviously it takes its toll on the court." Djokovic saved all four break points he faced on serve and broke Istomin three times -- in the third and ninth games of the first set and in the second game of the second set. Del Potro was not so fortunate, being forced to retire against Somdev Devvarman of India after losing the first-set tiebreaker 7-6 (3). Since winning the Sydney title last month, Del Potro has been struggling with a left wrist injury that has conjured up memories of similar pain he experienced in his right wrist four years ago. In 2010, the year after he won the U.S. Open, he played only three tournaments before and after surgery on his right wrist. Del Potro was fighting back tears in Dubai when he came to talk to the media after his retirement. "I dont feel really well," he said. "My wrist is hurting a lot and everybody knows what happened to me four years ago with my other wrist. "It was really tough to play today. I tried everything. I cannot be the player I would like to be." Having felt the pain in his left wrist during the Australian Open, Del Potro went at the end of January to consult with Dr. Richard Berger, who performed his right wrist surgery at the Mayo Clinic in Minnesota. The doctor recommended a course of physical therapy. Asked if he would have kept playing if he won the first set, Del Potro said: "I dont think so, no. It was hurting too much." Devvarman, a wild card who won a challenger in New Delhi last week, hit a service winner on his third set point in the tiebreaker. That proved to be the final point of the match. "Its unfortunate, especially for a guy like him," Devvarman said. "I realized he wasnt comfortable hitting backhands and I tried to make him hit as many as I could, and he wasnt really hitting over it so I knew he wasnt happy." Third-seeded Tomas Berdych extended his winning streak to eight matches with a 6-3, 6-4 win over Romanian qualifier Marius Copil. Berdych, who reached the final in Dubai last year, won the Rotterdam title two weeks ago. Fifth-seeded Jo-Wilfried Tsonga of France secured a 6-2, 6-4 win over Victor Hanescu of Romania. Jeremy Lin Raptors Jersey .com) - Ames, IA (SportsNetwork. Pascal Siakam Raptors Jersey . - All-Pro quarterback Aaron Rodgers looked spry enough in pregame warmups Sunday for Green Bays divisional playoff game against Dallas. https://www.raptorsrookiesshop.com/Malco...Edition-Jersey/. -- Another baseball tradition is about to largely disappear: a manager, with a crazed look in his eyes, charging the field and getting into a face-to-face shouting match with an umpire. Kawhi Leonard Jersey . He insists hes not counting. "If youre thinking hits, youre not paying attention to wins," Altuve said Sunday after leading the Houston Astros past the Texas Rangers 3-2. Kyle Lowry Raptors Jersey . With the Canadiens leading by one to start the third period, Price turned away 16 shots by the Panthers in the final frame to give Montreal a 2-1 victory over Florida on Monday night. The Panthers (16-21-6) outshot Montreal 16-10 in the final frame, but were repeatedly frustrated by Price, who made 26 saves on the night.DETROIT - Takuma Sato has earned the pole position for Sundays second race of the Detroit Grand Prix. Satos final lap in the second of two qualifying sessions knocked Helio Castroneves out of the top spot. Castroneves, who won the pole and finished fifth in Saturdays first race, will start third under the Indy Car series qualifying rules. Canadian James Hinchcliffe, the fastest driver in the eearly qualifying session, will share the front row with Sato.dddddddddddd. Will Power, who won Saturdays first race, will start eighth Sunday. It was another short qualifying run for Indianapolis 500 champion Ryan Hunter-Reay, who crashed on his first qualifying lap and will start 21st. He had the same starting spot a day earlier and finished 16 after crashing on the last lap. ' ' '