LOS ANGELES – German top seed Tommy Haas advanced to the semi-finals of the 700,000-dollar ATP Los Angeles Open with a 7-6 (7/3), 6-2 triumph over Russian eighth seed Marat Safin on Friday.

Haas advanced to a semi-final against US sixth seed Sam Querrey, who beat Israeli fourth seed Dudi Sela 6-3, 7-5.

Safin denied Haas on five break point chances early in the first set and broke the German at love in the seventh game for a 4-3 edge.

Haas, struggling with unforced errors, broke back in the eighth game but Safin broke again in the 11th game and served for the set but squandered three set points and wound up surrendering a break and the set in a tie-breaker.

Haas broke Safin for a 3-2 edge in the second set and again in the seventh game before holding in the last game to complete the victory.

US second seed Mardy Fish withdrew Friday with an abdominal strain, handing Argentina's Leonardo Mayer a walkover into the semi-finals, where he will meet Australian qualifier Carsten Ball, who ousted American John Isner 6-4, 6-4.

Fish struggled to outlast Australian Chris Guccione in a second-round match Thursday, rescuing three match points before rallying for a three-set victory. But the effort proved too much for Fish to continue in the hardcourt event, a tuneup for the US Open.