text: Two hours before the Miami Open semifinal, Novak Djokovic practiced his returns in an empty stadium, the ball coming at him quickly because his hitting partner stood three feet inside the baseline to emulate big-serving John Isner. The drill helped. Djokovic achieved a breakthrough service break against Isner and won Friday night, 7-6 (3), 6-2. 'He's probably the best server we have in the game,' Djokovic said. 'But I managed to get a lot of serves back. That was one of the keys in the match, making him play and getting into the rally and making him work extra.' Novak Djokovic beat John Isner in straight sets to reach the finalof the Miami Open on Friday night . The No 1-seeded Djokovic closed to within one win of his fifth Key Biscayne title and will face Andy Murray . The No 1-seeded Djokovic closed to within one win of his fifth Key Biscayne title. His opponent Sunday will be two-time champion Andy Murray, who defeated Tomas Berdych 6-4, 6-4. Djokovic became the first player in the tournament to break Isner, and managed another break two games later. He actually outserved the 6-foot-10 American, totaling 10 aces to nine for Isner, and never faced a break point. A taut, one-hour opening set created plenty of drama for the capacity crowd. Isner held despite several long service games and erased the only break point he faced late in the set, but he won only two of five points on his serve in the pivotal tiebreaker. Djokovic's biggest hole while serving was a love-30 deficit late in the first set. He responded with consecutive aces and escaped. Djokovic is aiming to win his fifth title in Miami and will take on Scotsman Murray in Sunday's final . Djokovic's first break gave him a 2-1 edge in the second set, and that margin grew to 5-1. He finished with just eight unforced to 31 by Isner, who lost 70 percent of his second-serve points. 'I needed to step in and use those opportunities,' Djokovic said. 'When I have his second serve, I'd better use it properly and try to be aggressive.' Djokovic won the Key Biscayne title in 2007, 2011, 2012 and 2014. Serena Williams bids for her eighth Key Biscayne title Saturday against Carla Suarez Navarro. Djokovic's biggest holin serving was a love-30 deficit late in the first, he responded with consecutive aces . Murray lost his first service game in each set but recovered and moved closer to his third Key Biscayne title by beating Berdych. Murray won the championship in 2009 and 2013, and was the runner-up in 2012. The Scotsman has a home in nearby Miami and practices on the Key Biscayne courts. 'I've obviously played some good tennis here over the years,' Murray said. 'The reason for that is because I'm extremely familiar with the conditions, with the surface, the way the court plays.' Aside from his two shaky service games, the No. 3-seeded Murray played almost flawless tennis against No. 8 Berdych, extending points with scrambling defense until the Czech would finally make a mistake. Djokovic won the Key Biscayne title in 2007, 2011, 2012 and 2014 and is now going for his sixth Miami crown . Murray, by contrast, totaled only eight unforced errors from the baseline. He improvised, too, winning points with unorthodox strokes requiring compound adjectives, such as a running shoetop-scoop lob and an underhand-swipe backhand drop shot. Murray fell behind love-30 serving in the final game but rallied and smacked winners on the final four points, including a nifty forehand volley and cross-court backhand. When a final forehand gave him the win, he screamed in jubilation and repeatedly pumped his arm like a piston. 'I just played a bit better than him. That was the difference,' Murray said. 'When I was behind in games, like the last game, for example, I came up with some big serves and was able to dictate a lot of the rallies from the baseline.' The final is Murray's first since he was runner-up to Djokovic at the Australian Open on February 1 . The final is Murray's first since he was runner-up to Djokovic at the Australian Open on February 1, and his first in two years at an ATP Masters 1000 tournament. He's 9-3 in Masters 1000 finals. Murray improved to 6-6 against Berdych and has won their past two matches. 'Andy changed the game plan a bit,' Berdych said. 'He started to play much more aggressive in the last two matches that he played me. Now I know what to expect and I'll just be more ready for it.'
target: Novak Djokovic beat John Isner 7-6. 6-2 in their Miami semi-final .
  The world No 1 will take on Andy Murray in Sunday's final .
  Djokovic is bidding to win his fifth title at Key Biscayne .