Fourth-seeded Milos Raonic hit 12 aces and saved all five break points he faced as he beat Steve Johnson of the United States 7-6 (4), 6-4 in the first round of the Swiss Indoors on Tuesday.
Tommy Robredo advanced to the second round of the Valencia Open by beating fifth-seeded John Isner 7-6 (3), 6-3 on Tuesday.
Rafael Nadal marked his return to the Swiss Indoors after a 10-year absence with a 6-2, 6-2 win over Italian qualifier Simone Bolelli in the first round on Monday.
Top-seeded Andrea Petkovic of Germany exited the Luxembourg Open in the first round on Tuesday, losing 6-4, 6-2 to Pauline Parmentier.
Ivo Karlovic of Croatia saved three match points in the second set before beating Federico Delbonis of Argentina 6-7 (1), 7-6 (9), 7-6 (2) on Tuesday at the Erste Bank Open.
Ana Ivanovic pulled out of the Generali Ladies with a left hip injury on Wednesday, one day after receiving medical treatment during her first-round win over Pauline Parmentier of France.
Top-seeded Jelena Jankovic overcame a second-set lapse to defeat Russian Alla Kudryavtseva 6-2, 0-6, 6-0 in the first round of the Tianjin Open on Tuesday.
Stefanie Voegele of Switzerland won the last three games to edge sixth-seeded Barbora Zahlavova Strycova of the Czech Republic 7-6 (4), 7-5 in the opening round of the Generali Ladies on Monday.
US Open champion Marin Cilic was eliminated in the first round of the Shanghai Masters, losing to Ivo Karlovic 7-5, 2-6, 7-6 (2) Monday.
Five-time winner Novak Djokovic pushed his all-time mark at the China Open to 20-0 after making quick work of Spain's Guillermo Garcia-Lopez in the first round Tuesday.
Japanese wildcard entry Tatsuma Ito upset Australian Open champion Stan Wawrinka 7-5, 6-2 on Tuesday to advance to the second round of the Japan Open.
Serena Williams narrowly avoided a bagel against Spanish qualifier Silvia Soler-Espinosa, then won 13 of the next 15 games to pull out a 7-5, 6-2 victory Monday in the first round of the China Open.
Rafael Nadal says the injured right wrist that sidelined him for two months and caused him to miss the US Open is feeling better and that he's ready to compete again.
Fifth-seeded Gilles Simon of France lost in the first round of the Shenzhen Open on Tuesday, falling to Ricardas Berankis of Lithuania 6-4, 6-2.
Rajeev Ram of the United States moved into the second round of the Malaysian Open by beating Australian qualifier Omar Jasika 4-6, 7-5, 6-3 Tuesday.
Juan Monaco of Argentina moved within one victory of his 300th career win on the ATP Tour, beating Federico Delbonis 6-3, 7-5 on Monday at the Shenzhen Open.