British number one Johanna Konta reached the semi-finals of the Italian opening with a 6-3 3-6 6-1 winner of Czech teenager Marketa Vondrousova.
On the 28th birthday, Konta, who sealed the last of his three WTA titles in 2017, won an hour and 53 minutes.
She faces Kiki Bertens in the last four after the Belgian advanced, because the world's number one Naomi Osaka pulled out with a hand injury.
Karolina Pliskova beat another former world number one, Victoria Azarenka.
Czech Pliskova will win the evening match between qualifiers Kristina Mladenovic from France and Maria Sakkari in Greece, which means there will be a qualification in the last four in Rome for the first time since Daria Gavrilova in 2015.
With Vondruosova showing the effects of two three-set matches the day before, Konta quickly took control and sealed the opening set with a full drop droplet online.
But after an emotional discussion with his coach, the teenager who won their only previous meeting at the hard courts in Indian Wells last year grabbed a loose game from Konta to break into the fifth game of the next.
A wild forehand from the British went wide and long to take the fight for a decision maker.
Konta, who also played two matches on Thursday, rescued a break in the second game with a backhand who cut the line and then broke in the next during six consecutive matches.
Osaka will remain the world's number one next week, following Simona Halep's second round exit to Vondrousova on Thursday.
Pliskova recorded his 500th career win with a 6-7 (5-7) 6-2 6-2 victory over Azarenka, leveling their head-to-head record of 4-4.
She wrapped up a two-hour victory 26 minutes to avenge a loss for Azarenka – who also has 500 career winners – in their recent meeting on the indoor clay courts in Stuttgart last month.
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