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.