Five-time major champion Iga Swiatek was on the end of a monumental shock as Filipina teenager Alexandra Eala continued her dream run to reach the Miami Open semi-finals.
Second seed Swiatek, playing with increased security in Miami after being verbally abused by an "aggressive and taunting" fan, was completely out of sorts as she lost 6-2 7-5 to the world number 140.
The 23-year-old's serve was broken eight times as she continually struggled to hold serve, while her baseline game was shaky and led to a host of forehand errors.
Eala, 19, remained composed and focused as she completed the biggest win of her career.
"It might be one of the biggest upsets I've been on the side of the court for," said former British number one Tim Henman, watching in his role as a Sky Sports analyst.
Poland's Swiatek recently spoke out about the emotional toll she has faced in recent months, having served a one-month ban for a doping offence and not wanting to "step on the court" as a result.
This defeat means she has not reached a final since winning the French Open in June.
Eala, who was given a wildcard to play in Miami, will play American fourth seed Jessica Pegula in the semi-finals after she defeated Britain's Emma Raducanu.
Next week Eala will break into the world's top 100 for the first time.
"My mind is really blank, I don't think I've processed what I've just done," Eala told Sky Sports afterwards.
"In the end I'm still the same player I was two weeks ago."
BBC