Kitzbuehel - Paolo Lorenzi of Italy has downed two-time former champion Robin Haase 6-2, 6-3 in the first round of the Kitzbuehel Cup on Tuesday.
The sixth-seeded Dutchman, who won the event in 2011 and '12, dropped serve early in both sets and failed to break Lorenzi's serve.
Last year's finalist, Juan Monaco, overcame a slow start to defeat Andrey Golubev of Kazakhstan 0-6, 6-2, 6-1.
The 81st-ranked Argentine won just five points on serve in the opener and trailed 6-0, 1-4 when the match was interrupted for an hour by rain.
Monaco will next play No. 7 Jarkko Nieminen of Finland, who beat Teymuraz Gabashvili of Russia 6-4, 6-4.
Also, David Goffin of Belgium defeated Kenny De Schepper of France 6-2, 6-4 to set up a second-round match against top-seeded Philipp Kohlschreiber.
Results from the second day of the ATP Kitzbuehel Cup on Tuesday (x denotes seeded player):
David Goffin (BEL) bt Kenny De Schepper (FRA) 6-2, 6-4
Jarkko Nieminen (FIN x7) bt Teimuraz Gabashvili (RUS) 6-4, 6-4
Paolo Lorenzi (ITA) bt Robin Haase (NED x6) 6-2, 6-3
Juan Monaco (ARG) bt Andrey Golubev (KAZ) 0-6, 6-2, 6-1