Updated

Four-time champion Roger Federer, long-time German crowd favorite Tommy Haas and last year's titlist Juan Monaco were among Thursday's third-round winners at the $1.44 million German Open Tennis Championships.

The top-seeded former world No. 1 Federer handled Czech qualifier Jan Hajek 6-4, 6-3 on the red clay at Am Rothenbaum.

Federer won only three of 13 break points and needed six match points to finish off Hajek, which he did with a seventh ace.

The 17-time Grand Slam champion Federer, who fell to No. 5 in the latest world rankings and is using a new racquet with a larger head size this week, will meet capable German Florian Mayer in Friday's quarterfinals.

Meanwhile, last year's Hamburg runner-up to the Argentine Monaco, the second- seeded Haas, cooled off last week's Bastad, Sweden, titlist Carlos Berlocq of Argentina 6-2, 6-4 and a fifth-seeded Monaco got past ninth-seeded Frenchman Benoit Paire 6-3, 2-6, 6-2.

Third-seeded Nicolas Almagro whipped fellow Spaniard Guillermo Garcia-Lopez 6-2, 6-3, while 14th-seeded Spanish left-hander Fernando Verdasco upset 6- foot-8 fourth-seeded Pole Jerzy Janowicz 7-5, 4-0, as Janowicz retired with a right arm injury. Verdasco was last week's Bastad runner-up to Berlocq.

Other third-round play saw Mayer take out 11th-seeded Spanish southpaw Feliciano Lopez 7-6 (7-1), 6-2, hot 12th-seeded Italian Fabio Fognini dismiss Spaniard Marcel Granollers 6-2, 6-4, and Argentine qualifier Federico Delbonis erase Russian veteran Dmitry Tursunov 6-4, 6-3. Fognini nailed down his maiden ATP championship in Stuttgart last week.

The other quarterfinals will pit Haas against Fognini, Almagro versus Monaco, and Verdasco against Delbonis.

The 2013 Hamburg titlist will earn $328,000.