Maria Sharapova into Sony Open semi-finals as Italy's Sara Errani is defeated in straight sets But most of the time I did, and that's why she kept coming back and kept playing really well out there. I feel very lucky that I'm through. She had her chances to win that second set - who knows what would have happened. I'm lucky to get to the next one and have a chance to be in the semis again. Stumble: Maria Sharapova turned in an error-strewn displau (Photo: GETTY IMAGES) Sharapova is bidding for her first win at the Florida event after four previous runner-up finishes, including back-to-back final defeats in each of the last two years. Standing in her way in the last four is Serbia's Jankovic, who beat another Italian, Roberta Vinci, 6-4, 6-7 (6/8), 6-3. In the men's draw, third seed David Ferrer came from a set down to beat Jurgen Melzer 4-6, 6-3, 6-0 and set up a semi-final with Novak Djokovic's conqueror, Tommy Haas. Ferrer dropped the first set despite going up a break, but was in control from there - particularly in the final set as he broke three times and dropped just four points on serve. "I was a little bit nervous in the first set and part of the second," Ferrer said. But I tried to fight every point, to be focused and I had a good feeling in the final of the second set and of course in the third one. In his third Miami semi-final, he will face veteran German Haas who followed up his win against Djokovic with a 6-3, 6-1 win over Gilles Simon. The remaining two men's quarter-finals, including Andy Murray v Marin Cilic, take place later today.