PATTAYA, Thailand — Seeds Elena Vesnina and Peng Shuai reached the quarterfinals of the Pattaya Open Thursday, joining unseeded Japanese veteran Kimiko Date Krumm who defeated Tadeja Majeric of Slovenia 7-6 (4) 6-3. Russia's Vesnina beat Thai wild card Nicha Lertpitaksinchai 6-3, 6-3, and Peng of China overcame a strong challenge from Romanian qualifier Alexandra Dulgheru to win 6-3 6-4. Vesnina struggled to make any impression on Lertpitaksinchai's serve in the early stages. The Thai gave up just one point in her first three service games and held a break point to lead 4-3, but she sent a forehand wide and then surrendered her own serve in the next game to leave Vesnina serving for the set. In the second set Lertpitaksinchai fought off four break points, broke for 3-1 and held two game points to lead 4-1. But Vesnina fought off that threat, levelled at 3-3 and went on to win the final 12 points of the match. Peng was stretched by Dulgheru, taking the first set but then allowing her momentum to slip. The Romanian took charge of the second set to lead 4-1, but Peng staged a gallant comeback to claim the next five games and a place in the last eight. Majeric twice served for the opening set against a stubborn Date-Krumm before losing the tiebreak. After five consecutive breaks of serve to begin the second set left Date-Krumm leading 3-2, she broke once more to close out the match. Flipkens advances Eighth-seeded Kirsten Flipkens of Belgium comfortably beat Yvonne Meusburger 6-1, 6-3 at the Open GDF Suez in Pris Thursday to set up a quarterfinal match against top-seeded Maria Sharapova of Russia. Elina Svitolina of Ukraine and Germany's Andrea Petkovic also advanced easily. Svitolina beat Galina Voskoboeva of Kazakhstan 6-1, 6-2 and next plays third-seeded Sara Errani who beat Karin Knapp 6-4, 6-3 in al all-Italian match, while Petkovic beat Frenchwoman Kristina Mladenovic 6-4, 6-2. Petkovic next faces either Frenchwoman Alize Cornet or lucky loser Barbora Zahlavova Strycova, who replaced second-seeded Petra Kvitova of the Czech Republic after she pulled out because of a sore throat. Federer to open Davis Cup series Roger Federer will open Switzerland's Davis Cup first-round match against Serbia by playing Ilija Bozoljac Friday, while Australian Open champion Stanislas Wawrinka faces Dusan Lajovic. Switzerland is an overwhelming favorite against Serbia, last year's finalist and the 2010 Davis Cup champion, which will be without Novak Djokovic. The second-ranked Serb decided to rest after losing to Wawrinka in the Australian Open quarterfinals. Lajovic at No. 102 is Serbia's highest-ranked team member. Federer was a surprising inclusion in the Swiss team, having played only one first-round match since 2004. He last represented Switzerland in September 2012, helping win a relegation playoff against the Netherlands. The series opens Friday on indoor hard court. Doubles are Saturday and reverse singles Sunday. — Agencies
