Wawrinka, who lost in the 2008 final to Novak Djokovic, defeated Russian Igor Kunitsyn 6-3, 6-4 Monday. Blake lost to Romanian Victor Crivoi 7-5, 6-2.
The only other seed who won Monday was Croat Marin Cilic, who beat Italian Flavio Cipolla 6-2, 6-2.
A match between Spaniard Tommy Robredo and Russian Marat Safin was postponed until Tuesday because of rain. Six matches were either suspended or postponed due to Monday's rain.
Sixteen first-round matches and three second-round matches are scheduled for Tuesday.
Copyright 2009 by United Press International.