Toronto (Canada) (AFP) - Serena Williamas had to survive a 25-minute game in the second set as she defeated Spain's Nuria Parrizas Diaz 6-3, 6-4 on Monday at the WTA Toronto Masters.
The 23-time Grand Slam champion was playing only her second match this season and her first on a hardcourt since the 2021 Australian Open some 18 months ago.
Williams saved four break points in the marathon eighth game of the second set before she held serve.
The 40-year-old American then served out for the victory after two hours.
Simona Halep swept the opening seven games on her way to a 6-0, 6-2 victory over Donna Vekic to also reach the second round.
Romania's former number one and two-time Canadian champion lost no time in collecting her triumph over the number 82 qualifier in 62 minutes on a day where rain threatened.
Halep, ranked 15th, handed Vekic a 10th defeat in her last 11 matches against a top-20 opponent.The Croat last defeated a member of the ranking elite at the Olympics last summer when she put out No.3 Aryna Sabalenka.
Halep added a 33rd match victory to her 2022 total as she advanced at one of the five WTA events she has won twice (2016, 2018).
The 15th seed leads the WTA with the most career wins at 1000-level tournaments on 180, ahead of Victoria Azarenka and now-retired Caroline Wozniacki on 177.