Philipp Petzschner into quarterfinals

IRVING, Texas -- In support of countryman Dirk Nowitzki, German tennis player Philipp Petzschner has been tweeting about how he refuses to shave his beard until the Mavericks make it back to .500.

Just like Nowitzki and the rest of the Mavs.

Petzschner also happens to be in town this week, not only to support his friend Nowitzki but also work on his cause at the Dallas Tennis Classic in Las Colinas, which sees the 28-year-old in the quarterfinals of the $125,000 Challenger Tour event thanks to a quality second-round win over fourth-seeded Viktor Troicki.

A wild-card entrant ranked No. 119 in the world, Petzschner scored a 6-4, 6-4 victory Thursday over Serbia's Troicki, who's ranked 44th. That sent Petzschner into Friday's quarterfinals against Belgian qualifier Olivier Rochus, who is ranked 150th and advanced with a 6-3, 6-1 victory over Colombia's seventh-seeded Alejandro Falla.

Also in Friday's quarterfinals, wild-card entrant Bobby Reynolds and qualifier Denis Kudla meet in a battle of Americans, with Kudla having prevailed in a third-set tiebreaker in each of his two first-round matches. In the bottom half of the draw, No. 3 seed Denis Istomin of Uzbekistan meets No. 5 Jurgen Melzer of Austria in one quarterfinal, with Ukranian qualifier Illya Marchenko meeting countryman Sergiy Stakhovsky in the other.

Melzer cruised to a 6-0, 6-4 victory over American wild card Robby Ginepri in Thursday's play, dealing Ginepri just his second loss in seven matches in Dallas over the past month-plus. Ginepri reached the singles final of the $100,000 Challenger of Dallas at T Bar M Racquet Club in February before losing the title match to former University of Tennessee star Rhyne Williams.

In the doubles bracket, meanwhile, two teams with local ties were ousted in second-round matches Thursday.

SMU alumni Adham El-Effendi (also a former Greenhill School student) and Darren Walsh suffered a 6-4, 6-3 loss to the third-seeded duo of France's Edouard Roger-Vasselin and Holland's Igor Sijsling, while former Baylor star Benjamin Becker and fellow German-turned-Dallas resident Mischa Zverev lost a 4-6, 6-4, 10-8 heartbreaker to top seeds Melzer and Petzschner.