While Victoria Azarenka pulled out with a right shoulder injury, Daniela Hantuchova withdrew due to illness.
Ana Ivanovic five routinely broke Daniela Hantuchova's serve in a 6-0 match that was over in a whirlwind 15 minutes, as the International Premier Tennis League got underway in Manila.
The world number five overcame a late surge from her opponent Daniela Hantuchova to register a 6-0, 6-4 victory.
Czech public radio and television reported that the players are mostly from lower divisions but that some are from the top Czech league.
Hantuchova, a 2008 Australian Open semi-finalist in her best Grand Slam run, has matched her best US Open showing from 2002 by reaching the final eight.
17-year-old qualifier Victoria Duval, a daughter of Haitian parents and ranked at 296, beat the 11th seed and 2011 champion 5-7, 6-4, 6-4.
Radwanska was joined in the quarter-finals by younger sister Urszula, who stunned sixth-seeded Serbian Jelena Jankovic 6-2, 4-6, 6-3
Hingis consistently showed the deft hands that made her a nine-time Grand Slam doubles champion. The 32-year-old is scheduled to play doubles with Hantuchova in four tournaments, including the U.S. Open.
Hingis, who won five Grand Slam singles titles and nine in doubles and was ranked number one in the world for a total of 209 weeks, says she didn't think she had the appetite for the training that would be necessary.
Slovakia's Hantuchova, who needed just 47 minutes to dispatch Paszek, set up a second-round clash with second-seeded Agnieszka Radwanska.
Radwanska, who makes no secret of her strong Catholic faith, was photographed in the "Body Issue" of ESPN Magazine in profile without a stitch, sitting in a lawn chair by a pool filled with tennis balls.
Hingis, winner of 43 WTA titles, retired twice. She first retired in 2003 at the age of 22 owing to recurring ankle injury before returning to the WTA Tour in 2006.
Sharapova and Flipkens will be replaced in the 28-player draw by world number 46 Daniela Hantuchova and Christina McHale, who is ranked 79th.
Fourth seeds Paes and Stepanek won the match, stretched to second day after being suspended due to rain, with a 7-6 (6) 6-4, 6-7 (1), 6-4 win after battling hard with the Italian-Israeli pair for three hours and five minutes.
The former world number five from Slovakia showed she still has remarkable resilience as she beat the sensational new girl - Donna Vekic - from Croatia 7-6 (7/5), 6-4.
In other second-round matches, fourth-seeded Tamira Paszek of Austria lost to American Alison Riske, 2-6, 6-2, 6-3, and eighth-seeded Urszula Radwanska of Poland was beaten by Croatia's Donna Vekic, 6-3, 6-2.