Reigning champion Novak Djokovic dug deep to avoid a shock exit at the hands of Alexandr Dolgopolov before powering into the quarter-finals of the Miami Open. The unseeded Dolgopolov - ranked 65th in the world, 64 places behind Djokovic - surprised the Serbian by winning a first-set tie-break and building a quick 4-2 lead in the second set. But Djokovic steeled himself and rallied to force a decider, which he wrapped up without much resistance from his deflated Ukrainian opponent. Novak Djokovic celebrates after securing a quarter-final place at the Miami Open . Novak Djokovic came back from a set down to reach the quarter-finals of the Miami Open on Tuesday . Alexandr Dolgopolov had both of his soles bandaged and won only three points in the final set . Djokovic claimed a succession of long exchanges in the second set to even the match and go on to win . The 6-7 (3/7) 7-5 6-0 triumph pits the world number one against David Ferrer in the last eight after the Spaniard saw off Gilles Simon 7-6 (7/5) 6-0 in a little over an hour and a half. Also through to the quarters are British number one Andy Murray and fourth seed Kei Nishikori. The Scot racked up a 500th career win by edging out Kevin Anderson 6-4 3-6 6-3 to book a meeting with Austrian Dominic Thiem, a 7-6 (7/5) 4-6 7-5 victor against Adrian Mannarino. Nishikori of Japan made light work of David Goffin and his 6-1 6-2 sees him progress to a match-up against big-serving American John Isner, who rallied to upset fifth seed Milos Raonic 6-7 (3/7) 7-6 (8/6) 7-6 (7/5) in a match which last two and three-quarter hours. David Ferrer celebrates after defeating Gilles Simon to book his place in the last eight . Simon is grounded after a fall during his defeat to Ferrer, who faces Novak Djokovic next . Andy Murray was given a celebratory cake to mark 500 wins on the ATP circuit after beating Kevin Anderson . Tomas Berdych also made it through to the quarter-finals by beating Gael Monfils . Kei Nishikori is also through to the last eight, defeating Serbia's Viktor Troicki . Czech challenger Tomas Berdych reached his sixth quarter-final of the season by beating Gael Monfils 6-3 3-2. The Frenchman conceded the match by retirement after suffering a heavy fall on court, and Berdych will meet Juan Monaco following the unseeded Argentinian's 6-3 6-3 conquest of Fernando Verdasco. In the women's competition, Carla Suarez Navarro lost the first set 6-0 but hit back to see off Venus Williams 0-6 6-1 7-5 and reach the semi-finals. There she will face Germany's Andrea Petkovic after the ninth seed beat Karolina Pliskova of the Czech Republic 6-4 6-2.
Novak Djokovic came from a set down to beat Alexandr Dolgopolov. The world No 1 remains in contention for his fifth Miami Open win. Dolgopolov became less mobile after receiving treatment to his feet. Djokovic faces David Ferrer next after Spaniard beat Gilles Simon. Andy Murray through after beating South Africa's Kevin Anderson.