Zagreb, Croatia (SportsNetwork.com) - Top seed Tommy Haas was among Thursday's second-round winners at the Zagreb Indoors tennis tournament.
The former world No. 2 came from behind to beat fellow German Benjamin Becker 4-6, 6-3, 6-3 at Dom Sportova.
Up next for Haas will be Russian qualifier Andrey Kuznetsov.
In other action involving top-four seeds, German qualifier Bjorn Phau upended second-seeded 2012 Zagreb champion Mikhail Youzhny of Russia 4-6, 7-5, 6-1, No. 3 German Philipp Kohlschreiber lost just six points on serve in dousing Kazakhstan's Andrey Golubev 6-4, 6-2, and No. 4 Croatian favorite Ivan Dodig took out 6-foot-10 compatriot Ivo Karlovic 7-6 (7-5), 6-3.
Another Day 4 upset came when Kuznetsov topped eighth-seeded Dutchman Igor Sijsling 1-6, 6-3, 7-6 (7-5).
Also in the round of 16, British lucky loser Daniel Evans bested German qualifier Michael Berrer 1-6, 6-1, 7-6 (7-4) and Israeli veteran Dudi Sela dropped Slovak Lukas Lacko 6-3, 6-2.
Friday's other quarterfinals will pit Kohlschreiber against Evans, the 2011 Zagreb champion Dodig versus fifth-seeded fellow Croat and reigning champ Marin Cilic, and Sela against Phau.
The three-time Zagreb titlist Cilic beat Austrian Jurgen Melzer in last year's final and also captured this event back-to-back in 2009 and 2010.