Tommy Paul set up a potential Italian Open semifinal with Jannik Sinner after beating Hubert Hurkacz 7-6 (7/4), 6-3 on Thursday to move into the last four in Rome.
American Paul came through a humdrum quarterfinal encounter to reach the Foro Italico semis, where he awaits one of Sinner or Casper Ruud, for the second straight year.
Sinner faces by far the toughest test since his return from a three-month doping ban when he takes on sixth seed Ruud in the first of two evening matches on centre court.
The world No 1 is yet to drop a set on home clay but Ruud is on a hot streak and eyeing a second straight 1000 Masters triumph after breaking his duck in Madrid earlier this month.
Norwegian Ruud has won more matches on clay than any other player on the men's tour in the last five years, and Sinner is still finding his feet after his suspension, accepted from the World Anti-Doping Agency for testing positive for traces of clostebol in March last year.
If Sinner gets through to the semis it will be the first time two Italians have reached the last four of a Masters 1000 tournament since the series' creation 35 years ago, with Lorenzo Musetti facing Carlos Alcaraz on Friday.
Sinner's compatriot Jasmine Paolini is also bidding to become the first Italian woman since her doubles partner Sara Errani in 2014 to reach the women's final in Rome.
Paolini is favourite to get past unseeded Peyton Stearns, but her American opponent has knocked out a succession of big names, including Naomi Osaka and fifth seed Madison Keys.
Coco Gauff and China's Zheng Qinwen, who beat world No 1 Aryna Sabalenka on Wednesday night, contend the other women's semi in the last match on centre court.