Marinko loses tight Washington tennis semi August 3, 2013 - 9:29AM A cramping Marinko Matosevic of Australia suffered a heartbreaking third-set tiebreaker loss to Russian Dmitry Tursunov on Friday in the quarter-finals of the ATP and WTA Washington Open. On Thursday, a week before his 28th birthday, Matosevic downed 13th-ranked Canadian Milos Raonic 7-5 7-6, following earlier good wins over fading big names James Blake and Nikolay Davydenko to set up the clash with Tursunov. Tursunov overcame 13 double-faults with the help of 15 aces to win 6-3 4-6 7-6 (7-4) to reach his second semi-final this season. The 61st-ranked Tursunov made it to the semis at Washington's hardcourt tournament for the first time since 2006. He will face eighth-seeded American John Isner who hit 18 aces and never faced a break point during a 6-7 (5-7) 6-4 6-4 comeback victory over No.16 seed Marcos Baghdatis of Cyprus. Isner, the runner-up at this hardcourt tune-up for the US Open in 2007, improved to 6-0 in quarter-finals in 2013. He's also 5-0 against 2006 Australian Open finalist Baghdatis. Andrea Petkovic of Germany reached the women's semi-finals with a 4-6 6-1 6-3 victory over Paula Ormaechea of Argentina. Petkovic, a former top-10 player whose career was sidetracked by injuries, had lost three of her previous four matches before arriving in Washington. The 64th-ranked Petkovic will play No.4 Alize Cornet for a berth in the final after the Frenchwoman defeated fifth-seeded Romanian Sorana Cirstea 7-6 (7-5) 6-2. Russian third seed Ekaterina Makarova is also through to the semi-finals after another Romanian Monica Niculescu retired with a left wrist injury in the opening set.