Zheng Qinwen continued to deliver in her breakthrough season as she advanced to the semi-finals of the WTA Finals in Riyadh on Wednesday with victory over Jasmine Paolini, while Elena Rybakina beat the already-qualified Aryna Sabalenka.

Picking up a 30th win from her last 35 matches, Chinese Olympic gold medallist Zheng swept past the fourth-seeded Italian 6-1, 6-1 in a mere 67 minutes.

Meanwhile, Kazakhstan's Rybakina claimed a consolation 6-4, 3-6, 6-1 victory over world number one Sabalenka, who had already secured her semi-final spot as the group winner on Monday.

Eliminated from the competition after losing her opening two matches, Rybakina found her form against Sabalenka – a much-needed confidence boost for the world number five after missing the majority of the second half of the season with allergies, insomnia and a back injury.

"It was a tough match and I'm really happy that I managed to win. I think it's nice to finish the year at least with one win against the world number one," said Rybakina, who shared a warm embrace with Sabalenka at the net.

It was only the second loss Sabalenka has suffered in her last 24 matches.

Sabalenka, 26, must wait to find out who she will face in Friday's semi-finals, but has reason to celebrate despite defeat as she clinched the year-end number one ranking as a result of Iga Swiatek's defeat to Coco Gauff on Tuesday.

However, the Belarusian said she will not let her new ranking distract her from the task at hand – lifting the WTA Finals trophy for the first time in her career.

"It's a really great feeling but I figured that last night and it didn't work really well tonight for me so I just want to focus on the current tournament to stay hungry and stay motivated – it's a big tournament and it's also one of my goals, so I'll focus on this goal," Sabalenka said Wednesday.