Top seed Dominic Thiem was knocked out the Rio Open in the first round on Tuesday, going down 6-3, 6-3 to Laslo Djere, a result that gave the unheralded Serbian his first victory over a top 10 player in his career. The world ranked No. 90 broke Thiem's serve five times in what was a surprisingly lackluster display from a man who has won eight ATP titles on clay. Thiem served five double faults in a tournament he won in 2017. In another upset, third seed Marco Cecchinato was beaten 7-5, 7-6(1) by Slovenian Aljaz Bedene. Cecchinato was on a high after winning the Argentina Open Sunday but he never hit the same heights against the unseeded Bedene. Tiafoe crashes out Frances Tiafoe's title defense wilted but Juan Martin del Potro looked fully recovered from his knee injury to cruise to a 6-3, 7-5 win over Yoshihito Nishioka in the first round of the Delray Beach Open Tuesday. The third-seeded Tiafoe looked to have the match against qualifier Dan Evans in hand when he served up 6-5 and 30-love in the second set but was instead broken by Evans, whose aggressive net play frustrated Tiafoe in the final two sets as the Briton eventually prevailed 3-6, 7-6(1), 7-5. Late drama arose when Evans served for the match up 5-4 in the third set but nerves appeared to get to him and he was broken amid a flurry of unforced errors. But Tiafoe was broken in the next game and Evans made sure not to make the same mistake twice, winning his final service game at love to set up a second-round match against tournament wild card Lloyd Harris of South Africa. Del Potro, who won the tournament in Florida in 2011, will next face big-serving American Reilly Opelka after last week's New York Open champion saw off countryman Tennys Sandgren 6-4, 6-0 earlier in the day. Top American men's player John Isner used his blistering serve to overwhelm Canadian Peter Polansky 6-3, 7-6(4) and advance to the second round. The second-seeded Isner fired 23 aces to Polansky's four and won 87 percent of his first serve points as he cruised to victory. Next up for Isner is a second-round meeting with unseeded Slovak Lukas Lacko on Wednesday. Adrian Mannarino, Andreas Seppi, Paolo Lorenzi, Jordan Thompson, Steve Johnson, Mackenzie McDonald, Guillermo Garcia-Lopez and Radu Albot also won their first round matches Tuesday. Federer to make clay court return at Madrid Open Roger Federer confirmed his participation for this year's Madrid Open Wednesday, marking his return to the European clay court season after two years away. The 20-time Grand Slam champion has not played this year since his Australian Open round of 16 defeat by Greek Stefanos Tsitsipas in January. Federer, whose sole French Open title came in 2009, has preferred to skip the European clay season over the last two seasons to manage his schedule. The 37-year-old Swiss is the second most successful player at the Caja Magica behind Rafa Nadal, winning three titles in 2006, 2009 and 2012. "Federer is one of the best players of all time, it's no secret," tournament director Feliciano Lopez said in a statement. "We are happy because his return to Madrid is a gift to the tournament, but above all the fans will be able to see a unique player in the Caja Magica. Having the Swiss player back on clay with Djokovic and Nadal is going to be unmissable."
