Wawrinka defeated qualifier Peter Luczak 6-3, 7-5 by winning nearly three-quarters of the points on serve. He lost just four points in four service games of the first set and finished off two of his five break-point chances to claim the second set.
Rain caused much of Wednesday's play to be postponed to Thursday and weather again was responsible for scheduling issues. The second-round match between top-seeded Nicolas Almagro and Jarkko Nieminen was suspended early in the first set.
Eighth-seeded Marcel Granollers and Andreas Haider-Maurer finished off second-round wins in matches that started Wednesday but had to be completed Thursday. Granollers stopped Igor Andreev 6-1, 6-3 and Haider-Maurer won the last four games of the second set and took the third of a 3-6, 6-2, 6-4 decision over Santiago Giraldo.
No. 4-seeded Fernando Verdasco ousted Frederico Gil 6-3, 6-2 while fifth-seeded Feliciano Lopez topped Daniel Gimeno-Traver 6-3, 6-4 and Julien Benneteau got past Matthias Bachinger 6-4, 6-4.
Wawrinka draws Granollers and third-seeded Mikhail Youzhny plays Haider-Maurer in the quarterfinals from the bottom half of the draw. Verdasco is to meet Bachinger and Lopez awaits the winner of the Almagro-Nieminen match.