Thiemo de Bakker followed fellow Dutchman Igor Sijsling into the second round of the ABN AMRO tournament on Tuesday when 2007 champion Mikhail Youzhny retired with a hip injury while trailing 4-1 in the third set.
Youzhny won the first set 6-3, before De Bakker's powerful serve brought him back into the match, winning the second set 7-6 (2).
Sijsling produced the first major upset of the tournament on Monday by ousting third-seeded Jo-Wilfried Tsonga.
Robin Haase, a semifinalist last week in Zagreb, could not make it three Dutchmen in the second round. He lost to Ernests Gulbis 6-2, 6-1 in just 50 minutes.
Also Tuesday, Frenchman Michael Llodra dropped out of the tournament because of illness before his match with Julien Benneteau.