Second-seeded Tommy Haas advanced to the quarterfinals of the German Tennis Championships by beating Carlos Berlocq of Argentina 6-2, 6-4 Thursday.
The German led 5-2 in the second set but dropped serve. He then wasted two match points on Berlocq's serve before using his fourth to close out the match, hitting a cross-court forehand winner.
Berlocq won his first title last week in Bastad, Sweden.
Juan Monaco, the fifth-seeded Argentine who beat Haas for the Hamburg title last year, defeated ninth-seeded Benoit Paire of France 6-3, 2-6, 6-2.
Haas will play Fabio Fognini of Italy, who beat Marcel Granollers of Spain 6-2, 6-4. Fognini won his first title last week in Stuttgart.
Monaco plays third-seeded Nicolas Almagro, who beat Guillermo Garcia-Lopez 6-2, 6-3.