The Ukrainian sixth seed recovered from an early setback in the deciding set to claim a 6-3, 3-6, 6-1 victory on Friday, ending Sabalenka’s campaign at the season-ending tournament.
Svitolina, who had won only one of her previous seven meetings with the Belarusian, delivered an impressive performance to record just her second career victory against the four-time Grand Slam champion.
Despite being broken in the opening game of the third set, the 31-year-old responded brilliantly, winning six consecutive games to complete the turnaround.
Her victory secured a semi-final meeting with Wimbledon champion Linda Noskova as she continued her pursuit of a second WTA Finals title, having previously won the competition in 2018.
Sabalenka struggled with her first serve throughout the contest and finished with 35 unforced errors, allowing Svitolina to take advantage of several opportunities.
The world number two initially recovered after losing the opening set, racing into a 5-1 advantage in the second before eventually holding on to win 6-3 and force a deciding set.
However, her momentum quickly disappeared as Svitolina raised her level and capitalised on the mistakes that continued to affect the Belarusian’s performance.
Sabalenka saved three match points in the final game, but Svitolina remained composed, producing two important aces before sealing the victory with an emphatic forehand winner.
Speaking after the match, Svitolina admitted that the mental challenge had been particularly difficult.
“It was an extremely tough match, especially mentally,” she said.
“I was just trying to play one point at a time and find my game, find the fighting spirit until the end … she gave me a few chances here and there so I could find my shots.”
Sabalenka Endures Disappointing Season
The defeat brought an underwhelming end to Sabalenka’s season despite her impressive achievements earlier in the campaign.
The Belarusian won three tournaments during the year, including the prestigious Sunshine Double after triumphing at Indian Wells and Miami in March.
However, she finished the campaign without a Grand Slam title after losing the finals of both the Australian Open and US Open.
She also surrendered her world number one ranking to Elena Rybakina.
Meanwhile, French Open champion Mirra Andreeva completed an unbeaten group-stage campaign with a convincing 6-2, 6-1 victory over Diana Shnaider.
The 19-year-old Russian needed just 56 minutes to defeat Shnaider, who replaced the ailing Karolina Muchova.
Andreeva, already guaranteed a semi-final place as a group winner, will face American fifth seed Jessica Pegula in the next round.
Their meeting will attract additional attention following an incident involving Pegula, who was overheard calling Andreeva a “diva” during a practice-court conversation with her coach.
Pegula subsequently apologised, while Andreeva appeared to take the comments lightly.
The American admitted that the incident could add an interesting storyline to their upcoming encounter, although both players had attempted to play down the controversy.
