Anderson fought past qualifier Emilio Gomez 6-3, 7-6 (7-2) n one of the four second-round matches played Wednesday.
In the other matches Wednesday, fifth-seeded Adrian Mannarino breezed past Victor Estrella Burgos 6-1, 6-2 and Ivo Karlovic eliminated third-seeded Igor Sijsling 6-3, 7-6 (16-14).
No. 1 seed Janko Tipsarevic will play his first match of the week on Thursday against Ruben Bemelmans.
Senate Democrats to pull all-nighter on climate change
Scarlett Johansson steps out with fiance after pregnancy reveal