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.