Dudi Sela’s run in the Sony Open in Miami came to a grinding halt on Friday with a 6-2, 6-4 loss at the hands of world No. 9 Janko Tipsarevic.After falling to No. 127 in the world last week, his lowest ranking in almost two years, Sela came through two rounds of qualification in Florida and defeated Australian Marinko Matosevic (51) to advance to the second round of the prestigious tournament.Reuters contributed to this report.However, he was outplayed by Tipsarevic on Friday, succumbing after one hour and 14 minutes. The Serb improved to 3-0 in his career against Sela, who hasn’t progressed past a second round of an ATP Tour tournament since last July.In other action, Novak Djokovic and Maria Sharapova both survived unscathed but the Sony Open lost two other Grand Slam champions on Friday when Victoria Azarenka and Juan Martin Del Potro exited the Miami tournament.Azarenka withdrew from her opening match because of an ankle injury she suffered playing at Indian Wells last week.“I’m very disappointed ... But I have to take my health into consideration,” said Azarenka, who won the Australian Open in January but has struggled with injuries since. “I tried everything I could but couldn’t make it. It’s an unfortunate part of our job.”Azarenka’s withdrawal proved an unexpected bonus for American teenager Lauren Davis, who failed to qualify for the tournament.She was given a ‘lucky loser’ pass into the event when Azarenka pulled out then saved three match points in defeating Madison Keys 6-1, 5-7, 7-6.Former US Open champion Del Potro, suffered a surprise 7-6 ,6-1 loss to Germany’s Tobias Kamke.The towering Argentine had two set points in the opening set but lost his way just a week after making the men’s final at Indian Wells.“He didn’t play obviously his best tennis,” said Kamke. “But still I think I did a good job and pretty satisfied with that.”There were no other major casualties amongst the top seeds, with Djokovic and Sharapova both winning in straight sets. Sharapova romped to a 6-2, 6-0 win over Canada’s Eugenie Bouchard while Djokovic cruised to a 6- 1, 6-0 victory over Lukas Rosol.Only Spain’s David Ferrer, the men’s third seed, had an easier time. He won in a walkover when Dmitry Tursunov pulled out.In early action on Saturday, No. 2 seed Andy Murray beat Australia’s Bernard Tomic 6-3, 6-1.Roger Federer and Rafael Nadal are both missing from the field in Miami, with the Spaniard pulling out of the tournament after last week’s triumph at Indian Wells, while Federer decided to take an extended break before the start to the clay-court season.