Karlovic hits record-equaling 44 aces at Zagreb Indoors
The towering Karlovic matched the record of Mark Philippoussis in the number of aces in a best-of-three match, beating Brands 6-7 (4), 7-5, 7-6 (3).
Australian Philippoussis delivered 44 aces in Kuala Lumpur in a 1995 match against Byron Black of Zimbabwe.
Earlier Tuesday, Michael Berrer of Germany defeated Croatia's Borna Coric 6-4, 3-6, 6-4.
In other matches, Germany's Bjorn Phau defeated local hope Ante Pavic 6-3, 6-4, Dusan Lajovic beat fellow Serb Pedja Krstin 6-2, 6-3 and Lukas Lacko of Slovakia defeated Jan-Lennard Struff of Germany 6-4, 6-4.