Seeded players Marin Cilic and Kei Nishikori collected first-round wins Monday at the Italian Masters tennis tournament in Rome.
Grigor Dimitrov ousted world No. 1 Novak Djokovic in a three-set marathon Tuesday in a second-round match at the Madrid Open.
Pablo Andujar upended 10th-seeded Marin Cilic and No. 16 Gilles Simon also advanced Sunday, opening the men's singles competition at the Madrid Open.
Ivan Dodig claimed a second-round upset of No. 2-seeded Marin Cilic in Wednesday's play at the BMW Open tennis tournament in Germany.
Radek Stepanek and Gael Monfils came away with first-round upset wins Tuesday at the BMW Open tennis tournament in Germany.
Andrey Golubev and Yuriy Schukin kept Kazakhstan's Davis Cup hopes alive with a straight-set win Saturday in doubles over the Czech Republic.
Jan Hajek and Lukas Rosol posted wins Friday that put the Czech Republic up 2-0 in its best-of-five Davis Cup quarterfinal versus Kazakhstan.
Defending champion Czech Republic will use Jan Hajek and Lukas Rosol for its Davis Cup singles matches this week in a quarterfinal series in Kazakhstan.
Stanislas Wawrinka was given the leadoff spot for Switzerland in a first-round series this weekend against defending Davis Cup champion Czech Republic.