Caroline Wozniacki ousted Anastasija Sevastova in a three-set tussle to reach the quarter-finals of the Internazionali d'Italia.
The Dane appeared on course to progress in straight sets in the final match on court in Rome on Thursday, only to allow her opponent to rally back from the brink of defeat and force a decider.
However, having wasted a set-point opportunity on her way to losing the second, Wozniacki eventually triumphed 6-2 5-7 6-3 after two hours and 16 minutes on court.
While the world number two was pushed all the way, Simona Halep - who occupies top spot in the rankings - progressed without hitting a ball after Madison Keys was forced to withdraw before their meeting due to a rib injury.
Halep will next face Caroline Garcia, who overcame a second-set fightback from reigning US Open champion Sloane Stephens to triumph 6-1 7-6 (9-7).
Anett Kontaveit ended Venus Williams' hopes of glory once again, Angelique Kerber dropped just two games in dismissing Maria Sakkari and Maria Sharapova knocked out Daria Gavrilova in straight sets.
Elina Svitolina fought back from a poor first set to see off Daria Kasatkina 0-6 6-3 6-2, while Jelena Ostapenko also went the distance in her 2-6 6-3 6-4 victory over Johanna Konta.
MARIA ON THE MARCH
Sharapova's success means she is through to the quarter-final stage for a second successive tournament, having also reached the same stage in Madrid last week.
Crucially, though, the result against Gavrilova - who turned in an impressive display considering her previous match with Garbine Muguruza did not conclude until the early hours of Thursday morning - also means the Russian is projected to be seeded at the French Open.
"I just like the way that I'm competing," Sharapova told the WTA Tour's website after the 6-3 6-4 result. "I like the way that I feel out there. I think that's really important, you know.
"It's an inner feeling, sometimes maybe not something you can put into words. But I just like the attitude with which I am playing with."
Kontaveit is turning out to be Williams' nemesis on clay, knocking out the eighth seed again after one hour and 19 minutes on court.
The Estonian had battled back from a set down to see off her experienced opponent in the opening round in Madrid last week, yet this time her progress was a little more straightforward.
Making use of her ferocious backhand, Kontaveit dominated the first set and while Williams put up more resistance in the second, the veteran American succumbed in a tie-break to tumble out of the tournament.