Venus Williams has been knocked out of the Miami Open at the quarter-finals by the qualifier Danielle Collins 6-2, 6-3.
Seven-time Grand Slam winner Williams went a break down in the first set as American Collins raced to a 3-0 lead, and saved two set points at 5-2 but lost the third after 39 minutes.
The second set went a similar way with Collins, ranked 93rd, breaking at the first opportunity for a 2-0 lead, but Williams broke back for 2-1.
But Collins, 24, broke to take a 4-2 lead and booked her place in the semi-final on the second of her match points.
She will face French Open champion Jelena Ostapenko, who won a tight straight sets victory over Elina Svitolina.
Latvian Ostapenko needed successive tie-breaks to see off the world number four, eventually prevailing 7-6, 7-6 following two lengthy sets which lasted almost an hour each.