Roger Federer survived a brave challenge from American qualifier Frances Tiafoe before emerging with a 7-6 (7-2), 6-3 victory as he got his Miami Open title bid underway Saturday. Tiafoe, ranked 101st in the world, struggled against Federer's serve but was strong on his own and forced a first set tie-break in which the Swiss came out on top. The 19-year-old son of immigrants from Sierra Leone then broke Federer's serve in the first game of the second set only for the 18-times Grand Slam winner to break back twice and run out a comfortable winner in the end. Federer was full of praise for his opponent and said he would have gained valuable experience from the contest. "I hope he's going to learn a lot from a match like this just because playing on a center court with a lot of people, under pressure, saving break points, making break points, playing breakers. That's what it's about, and it should feed a player like him with a lot of energy moving forward," he said. Reigning US Open champion Stan Wawrinka got off to a solid start, beating Argentina's Horacio Zeballos 6-3, 6-4 at Crandon Park on Saturday. In the absence of Andy Murray and Novak Djokovic, the top two ranked players in the world, Wawrinka is the No. 1 seed and is fired up after reaching the final at Indian Wells last week, where he was beaten by Federer. "I'm happy the way I was moving, the way I was playing, and my attitude in general was really positive," added Wawrinka, who next faces Tunisia's Malek Jaziri, a 6-3, 4-6, 6-3 winner over Spain's Feliciano Lopez. Australia's Nick Kyrgios also progressed Saturday enjoying a 6-4 6-3 win over Bosnian Damir Dzumhur. Fifth-seed Agnieszka Radwanska had her bid to repeat her 2012 success at the Miami Open ended by Croatian veteran Mirjana Lucic-Baroni at 6-0 6-3. But second-seed Karolina Pliskova fought past Yulia Putintseva of Kazakhstan 7-5, 6-3 to move into the last 16 and Slovak Dominika Cibulkova also progressed with a comfortable two sets win over Belgium's Kirsten Flipkens. Lucic-Baroni is enjoying an unexpected upturn in her fortunes at the age of 35 and in January reached the semifinal of the Australian Open — 18 years after her previous appearance in the last four of a slam, in 1999 at Wimbledon. Spain's sixth seeded Garbine Muguruza is doing it the hard way in Florida this week. After battling back to beat American Christina McHale in three, rain interrupted, sets Friday, the Caracas born Muguruza had to pull out the stops again to deal with China's Zhang Shuai 4-6, 6-2, 6-2 in just over two hours. "It's very tough, especially the first round with players that you don't maybe play a lot. They are very good players as well. The difference is not that big. They play very well and you are in danger all the time," said Muguruza. "I'm just going through these situations with the best attitude possible, being humble, trying to accept it, and find my way," he said. The Spaniard will face the winner of Saturday's scheduled later game between Romanian Sorana Cirstea and Caroline Wozniacki.
