Wawrinka, the 2005 Gstaad runner-up, beat Argentine Federico Del Bonis 6-4, 7-5, and the fourth-seeded Hanescu beat Czech Ivo Minar 6-2, 6-2. Hanescu won over Russian Igor Andreev in last year's finale.
Two other seeds advanced on Day 3. No. 5 Frenchman Jeremy Chardy defeated countryman Thierry Ascione 6-3, 6-3, and No. 6 German Nicolas Kiefer beat Argentine Jose Acasuso 7-6 (7-5), 6-2.
In an upset, Brazilian Marcos Daniel nipped eighth-seeded Frenchman Paul-Henri Mathieu 7-6 (7-3), 7-6 (8-6). Mathieu was last week's runner-up in Hamburg and won this event two years ago.