Serena Williams survived a scare to reach the Wimbledon semi-finals with a comeback victory over hard-hitting Italian Camila Giorgi.
The 23-time Grand Slam champion dropped her first set of the championships but came through 3-6 6-3 6-4.
Giorgi, the world number 52, produced the type of power normally associated with her opponent - but the American then found an extra gear.
Williams faces German 13th seed Julia Gorges in Thursday's semi-finals.
Also through to the last four are German 11th seed Angelique Kerber, who beat Russian Daria Kasatkina 6-3 7-5, and Latvian 12th seed Jelena Ostapenko, who overcame Slovak Dominika Cibulkova 7-5 6-4.
Before the match, Giorgi had raised eyebrows when, asked about her impression of Williams over the years, she said: "I don't follow tennis."
And she certainly played as if undaunted by the reputation and titles of her opponent.
Giorgi's serve was straight out of the Williams book of power. She delivered three aces to the American's one in the first set and won 84% of points on her first serve.
It is not often you see Williams scrambling to return a serve or nearly knocked off her feet by the force of a near 120mph delivery - it is more often her dishing that up - but she was given a taste of her own medicine by the fearless Giorgi.
The 36-year-old came forward to attack more in the second set, not allowing Giorgi any break points and winning her own break in the fourth game.
She turned the screw with a backhand winner down the line to break in the third game of the final set and got more of her first serves in to take charge, sealing victory on her first match point when Giorgi sent a forehand into the net.