Robredo, seeded second, beat Poland's Michal
Przysiezny 7-5, 6-2.
"For me, the first match in a tournament is always difficult
and it's important not to take much risk," said Davydenko, who won the Warsaw Open in 2006.
The clay-court tournament, previously held in the northern
Polish city of Sopot, is the country's only event on the ATP Tour
and has a total prize pool of $628,800.
Robredo, who won his second Warsaw title last year, had to work hard in the
first set to overcome Przysiezny.
"He was playing very good at the beginning. I had to keep
pushing and get the break," said Robredo, who will face
American Wayne Odesnik in the second round.
Fourth-seeded Gilles Simon of France lost to Belgian qualifier Christophe Rochus 6-1, 3-6, 6-3. Rochus fell from the top 100 more than a year ago to No. 194 and has moved up to No. 115 with success on the challenger circuit.
Third-seeded Juan Monaco beat Polish wild card Jerzy Janowicz, 6-4, 6-3.
Information from Reuters and The Associated Press was used in this report.