Garbine Muguruza was thrashed by China’s Wang Qiang after arguing with her coach during the WTA Elite Trophy semi-finals in Zuhai.
Two-time Grand Slam champion Muguruza called Sam Sumyk on court after being broken to trail 3-2 in the opening set.
The two had a heated conversation which led to Sumyk saying “I don’t talk to people who are upset” and leaving the court during the change of ends.
The Spaniard then lost the next nine games as Wang triumphed 6-2 6-0.
Wang, who only played in the semi-final after Madison Keys withdrew with a knee injury, will play Australia’s Ashleigh Barty in the final.
Barty overcame German defending champion Julia Gorges 4-6 6-3 6-2.
Muguruza struggled on serve from the start and saved two break points before Wang finally made the breakthrough in a game lasting 11 minutes.
The former world number one looked short of confidence after the row with Sumyk.
She finished with just 14 winners to Wang’s 34, as well as 21 unforced errors.