Tipsarevic dropped his serve just once in a 6-3, 6-3 win over Santiago Giraldo. The only break Tipsarevic suffered erased a second-set advantage but he won the next three games -- two on breaks.
Guillermo Garcia-Lopez earned the spot opposite Tipsarevic in the quarterfinals with a 1-6, 6-3, 6-4 decision over Sergiy Stakhovsky. After the shaky first set, Garcia-Lopez won 56 percent of the points the rest of the way, including more than 70 percent on serve.
Hanescu will play Mayer in Friday's quarterfinal round.
The quarterfinals decided Wednesday have second-seeded Gilles Simon, the tournament defending champion, playing Daniel Brands and eighth-seeded Viktor Troicki going against Lukas Rosol.