Aryna Sabalenka became the first player to secure a semi-final spot at the WTA Finals by defeating the resilient Jasmine Paolini in straight sets.

Top seed Sabalenka won 6-3, 7-5, confirming Elena Rybakina's exit from the season-ending tournament in Riyadh, Saudi Arabia.

Earlier on Monday, Kazakh player Rybakina was beaten 7-6 (7-4), 3-6 and 6-1 by Olympic champion Zheng Qinwen, her second final defeat, and needed a Paolini win to keep her hopes alive receive.

But a tough win over the Italian, which secured her two set points, brought Sabalenka one step closer to her first WTA Finals title and world number one at the end of the year.

Should she beat Rybakina in her final purple group game on Wednesday, the Belarusian will remain at the top of the table until 2025, out of Iga Swiatek's reach.

“The whole game was tough,” said the 26-year-old Sabalenka. “(Paolini) is such a great player, puts so much pressure (on me) and moves well.”

With an early double break of serve, Sabalenka – a two-time Grand Slam winner in 2024 – came through against Paolini and although she was able to cancel out one of those breaks, the 28-year-old fourth seed was hardly able to challenge her powerful opponent.

However, the second sentence told a different story. Despite completing four straight games after an early break for Paolini, Sabalenka became frustrated when the Italian – who was enjoying a breakthrough season on the WTA Tour – staged a comeback to take a 5-4 lead.

But after saving two set points, a switch was flipped for Sabalenka, who immediately broke Paolini's serve again before ending the game straight away.

“The second set was pretty difficult. I just tried to stay aggressive and show her that I will fight for this set no matter what,” Sabalenka added.

“I’m really happy to finish this game in straight sets.”

The WTA Finals will be held in Saudi Arabia for the first time – a move that has been criticized by some because of the human rights situation in the country.

This year's tournament has record prize money, with the individual winner expected to pocket around £4 million.

In the Orange Group, Jessica Pegula will face Barbora Krejcikova on Tuesday before defending champion Swiatek plays against Coco Gauff.