MIAMI: World number one and three-time defending champion Serena Williams and second-ranked Andy Murray both crashed out of the ATP and WTA Miami Open on a Monday (Mar 28) filled with upsets.Russian 15th seed Svetlana Kuznetsova stunned 21-time Grand Slam champion Williams 6-7 (3/7), 6-1, 6-2 while British world number two Murray dropped a third-round match to Bulgarian 26th seed Grigor Dimitrov 6-7 (1/7), 6-4, 6-3.Williams and Murray each made 55 unforced errors, fading in the third set when it mattered most. “A lot of unforced errors crept in and he was a lot more solid than me,” said Murray, who had 22 unforced errors in the third set alone. “I made many more mistakes than usual, especially in the third set.”Williams’ struggles prompted questions about her fitness and movement, irking the 21-time Grand Slam champion. “I don’t think it’s appropriate to criticise my movement right now,” Williams said. “I did the best I could. I can’t win every match. These players come out and give their best. I have to give 300 percent every match.”The 34-year-old American was seeking her ninth Miami crown but instead matched her earliest-ever exit from 2000 with a fourth-round departure. “It’s obviously disappointing, but…