seeded Juan Martin del Potro won his 16th consecutive match in beating Dudi Sela 6-0, 5-7, 6-2 on Wednesday to reach the quarterfinals of the Legg Mason Classic. Fourth-seeded Tommy Haas also advanced, beating Nicholas Mahut of France 7-6 (4), 6-3. Del Potro cruised through the opening set, struggled in the second, and broke Israeli Sela a sixth time for the match. The 19-year-old Argentine, ranked a career-high No. 19 in the world, has not lost in six weeks. Del Potro has won all three tournaments he's entered. He picked up his first career title in Stuttgart, Germany, and kept the streak going with wins in the Austrian Open and Los Angeles last weekend. Del Potro will meet last year's runner-up, John Isner, in the quarterfinals. Isner defeated Donald Young 6-4, 7-6 (4) in an all-American affair. Young was overpowered by the 6-foot-9 Isner's serve. Isner had 17 aces in the match, and Young was visibly frustrated at the end of the tiebreaker. After hitting a long unforced error to go down 5-4 in the tiebreaker, Young threw his racket to the ground. After failing to return Isner's next serve, Young kicked the racket before going to his bag for a new one. The new racket didn't help Young, who returned Isner's final serve wide to send Isner to the showdown with del Potro. In contrast to del Potro, who cruised early before running into trouble, Haas had his tough times early in the match. Serving with a 5-3 lead in the first set, he double-faulted three times to give Mahut a break. Those were just the most damaging of seven double faults for Haas in the opening set. The German said his shoulder was a little bit tight, and after he missed on a few serves he started to overthink the motion. Haas settled in after the first-set tiebreaker, winning the final four games of the second set to end the match. He had no double-faults in the second set. Haas will face Alejandro Falla after the Colombian prevailed against Florent Serra of France 7-6 (2), 7-6 (11) in 2 hours, 26 minutes. Srebotnik upset In Cincinnati, unseeded Nathalie Dechy rolled through a third-set tiebreaker to pull out a 7-5, 2-6, 7-6 (1) upset of fourth-seeded Katarina Srebotnik and reach the Cincinnati Women's Open quarterfinals on Wednesday. Dechy won the first five points of the tiebreaker before connecting on a forehand volley at match point to clinch her third win in five career matches against Srebotnik. Third-seeded Maria Kirilenko avoided an upset with a 1-6, 6-2, 7-5 win over Canadian qualifier Stephanie Dubois 1-6, 6-2, 7-5 in their second-round match. Second-seeded Nadia Petrova, the highest seed remaining after No. 1 Marion Bartoli retired on Tuesday with abdominal pain, also advanced by easily beating Julie Ditty of the US 6-1, 6-1. Kirilenko will play Sabine Lisicki of Germany, who beat Camille Pin of France 6-3, 6-4. Petrova will play American wild card Lilia Osterloh, who reached the quarterfinals of the Western and Southern Financial Group Women's Open for the second consecutive year, this time with an easy 6-4, 6-1 upset of Petra Cetkovska of the Czech Republic.
