Aryna Sabalenka and Jessica Pegula make winning starts at WTA Finals

Sabalenka made short work of Maria Sakkari in the opening match in Mexico. The Belarusian won the first 11 games before Sakkari, a replacement for the injured Karolina Muchova in the season-ending championships, got on the board.

Last year's beaten finalist completed the job 6-0 6-1 in windy Cancun to open her group matches with a win.

"The score looks really easy, but it wasn't an easy match," said Sabalenka.

"I'm super happy to win this match, especially against Maria, someone who was such a big fighter and all these tough matches against her."

Sakkari admitted it was a bad day at the office.

"I just haven't been feeling my game so well, maybe because I had too much time off after China and not too many days on the court since I came back," she said.

"Maybe that's a factor. I don't know. I think it was pretty obvious that I was not feeling my game, not feeling comfortable out there. Just a very, very bad day in the office, and hopefully it's gonna get better for Tuesday."

Meanwhile, Pegula fought back from a break down in the first set to beat world number four Elena Rybakina 7-5 6-2.

Trailing 5-3, Pegula won four games in a row to clinch the first set and continued her record of not losing a match this year after going a set up.

Play in the other group begins on Monday night with world number two Iga Swiatek taking on Marketa Vondrousova before US Open champion Coco Gauff takes on Ons Jabeur.

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