Miami MastersTop men and women’s seeds continued their march at 2015 Miami Masters as many of men’s third-round and women’s fourth-round matches were completed. Djokovic and Serena cruised into their next rounds without much trouble as did Kei Nishikori, Milos Raonic, David Ferrer, David Goffin, Gilles Simon and Alexandr Dolgopolov. But Grigor Dimitrov was halted in his tracks by John Isner. In two notable upsets among women, Venus Williams came up with a great performance against the Dane Caroline Wozniacki and Spain’s Carla Suarez Navarro saw off Agnieszka Radwanska. Most other women’s seeds went through to the quarterfinals on Monday.

Defending champion and men’s no.1 seed Novak Djokovic moved to the round of 16 with an easy victory over Belgium’s Steve Darcis. Djokovic, who is bidding for his fifth title at Miami Masters, ran through the one-sided first set in just 26 minutes. Darcis, however, tested the champion with a sterner second set. The Belgian broke Djokovic to go ahead 5-4 but after the Serb broke back to level at 5-5, he raised his game to break once more and held his serve to secure the match at 6-0, 7-5. Djokovic’s fourth round opponent will be Ukraine’s Alexandr Dolgopolov, who came through after beating Brazil’s Thomaz Bellucci 7-5, 6-4 in his third round match.

Japan’s no.4 seed Kei Nishikori had little trouble in getting past Serbia’s Viktor Troicki 6-2, 6-2 in just over an hour. Troicki, who required some medical attention during the match, found it difficult to cope with Nishikori’s superior game as the Japanese converted 5 break points out of 6 that came his way. For a place in the quarterfinals, the 25-year old Japanese will take on Belgium’s no.18 seed David Goffin, who defeated Poland’s Jerzy Janowicz 6-4, 6-3.

Canada’s no.5 seed Milos Raonic also moved into the fourth round with a hard-fought 6-1, 5-7, 7-6 victory over no. 31 seed Frenchman Jeremy Chardy. Raonic had taken the first set easily at 6-1 but he was broken just as he prepared to serve for the match at 5-4 in the second set. Chardy reeled off three points in a row and forced a decider. The two players had a good third set before Raonic emerged victorious in the tiebreak. Raonic will now face USA’s 22nd seeded John Isner, who caused an upset by defeating ninth seeded Bulgarian Grigor Dimitrov 7-6, 6-2. Isner played a powerful game against the Bulgarian in sending down 15 aces and getting 73 percent of his first serves in play. Dimitrov’s game got scrambled in the second set as he could only manage just 40 percent of his first serves in. Spain’s sixth seed David Ferrer got past Czech Lukas Rosol 6-4, 7-5 to set up a clash with Frenchman Gilles Simon, who defeated Colombia’s Alejandro Falla 6-3, 6-4.

Among women, top-seeded Serena Williams played a forceful game against Russia’s Svetlana Kuzetsova, who couldn’t prevent her 6-2, 6-3 rout by the defending champion. Serena looked fit on court and free from the knee trouble, she faced at Indian Wells a few days ago. In the quarterfinals, Serena will contend with Germany’s Sabine Lisicki, who dropped just three games in her 6-1, 6-2 triumph over no.11 seed Italian Sara Errani.

However, there were two notable upsets on the WTA side. The first to fall was Denmark’s no.4 seed Caroline Wozniacki, who lost to 15th-seeded Venus Williams 3-6, 6-7. For a place in the semifinals, Venus will face Spain’s Carla Suarez Navarro, who upset no.7 seeded Agnieszka Radwanska 5-7, 6-0, 6-4 to reach the quarterfinals.

In other fourth round matches for women; no.3 seed Simona Halep beat Flavia Pennetta 6-3, 7-5; American Sloane Stephens defeated Switzerland’s Belinda Bencic 6-4, 7-6; Andrea Petkovic of Germany beat Russian Ekaterina Makarova 6-1, 7-5 and Czech Republic’s Karolina Pliskova defeated Russia’s Daria Gavrilova 6-3, 6-2.