US top seed John Isner fired 21 aces in advancing to the ATP Hall of Fame Championships semifinals with a 7-6 (7-5), 6-4 victory over fifth-seeded countryman Alex Bogomolov Thursday. Wild-card entrant Isner lost his first matches in 2007 and 2008 in his only other visits to the Newport grass but never saw a break point over 94 minutes in his third victory this week to reach his first ATP semifinal of the year. On Saturday, 46th-ranked Isner will face German eighth seed Tobias Kamke, who reached his first career ATP semifinal by ousting France's Edouard Roger-Vasselin 3-6, 6-1, 6-3. Kamke, last year's ATP Newcomer of the Year, needed 98 minutes to advance, improving to 8-12 this season. He reached a career high of 64th in the rankings but has since slid to his current ranking of 96th. Argentina in semis In Buenos Aires, Juan Ignacio Chela and Eduardo Schwank led Argentina into their second consecutive Davis Cup semifinal Friday by defeating Evgeny Korolev and Yuriy Schukin 6-3, 6-2, 7-5 in the doubles for an unassailable 3-0 lead over Kazakhstan. Juan Martin del Potro and Juan Monaco had given the South Americans a 2-0 advantage with straight-set victories in the opening singles Thursday. The tie, played on clay at Parque Roca, was rescheduled for July 7-9 due to municipal elections on the Sunday. Serbia ahead In Halmstad, Sweden, Davis Cup holder Serbia shrugged off the injury-enforced absence of Wimbledon champion Novak Djokovic to take a 1-0 lead over Sweden in their Davis Cup quarter-final on Friday. Viktor Troicki beat Michael Ryderstedt 6-3, 6-1, 6-7 (6/8), 7-5 in the first singles rubber, just hours after new world No. 1 Djokovic pulled out of his rubber against Ervin Eleskovic citing a knee injury. Britain on track In Glasgow, Andy Murray bounced back from his Wimbledon disappointment Friday to help Great Britain grab a share of the spoils in the opening singles of its Davis Cup clash with Luxembourg. World number four Murray barely broke sweat as he crushed lowly ranked Laurent Bram 6-0, 6-0, 6-0 to level the match at 1-1. Earlier Ward had started slowly before being downed by Muller 6-3, 7-6 (7-4) 6-1 in the opening rubber. Federer struggles In Berne, Roger Federer came from a set behind to beat feisty Portuguese Rui Machado, ranked 90 places below him, as he made his Davis Cup return for Switzerland after an absence of nearly two years on Friday. Federer, playing in front of a crowd which produced the occasional yodel but where cow bells were noticeably absent, faced 14 break points and produced 48 unforced errors in his 5-7, 6-3, 6-4, 6-2 win. His win gave Switzerland a 2-0 lead on the first day of the European zone tie after Stanislas Wawrinka had beaten Frederico Gil in the opening match.
