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'v e been on the side of the court for," said former British number one Tim Henman, watching in his role as a Sky Sports analyst.