Teenager Lorenzo Musetti soundly beat Stan Wawrinka 6-0 7-6(2) on Tuesday, winning for the first time on the professional circuit in the first round of the Italian Open.
It was only a second game on the ATP Tour for the 18-year-old Italian, who came through three rounds of qualifying, before aggressively upending the 35-year-old Swiss.
He has now set up a second-round meeting with Japan’s Kei Nishikori.
Wawrinka, a three-times Grand Slam champion, made a string of errors as he lost the first eight games before working his way back into the game.
Musetti, however, held his nerve to take the second set tie-break and the match.
Earlier, Denis Shapovalov and Andrey Rublev had cruised into the second round with emphatic straight-sets victories.
Canadian 12th seed Shapovalov, who reached the U.S. Open quarter-finals last week, shook off jet lag to beat Guido Pella 6-2 6-3, firing seven aces and 23 winners past the Argentine.
Ninth seed Rublev, making his debut at the Foro Italico, beat qualifier Facundo Bagnis 6-4 6-4 to book a spot in the second round where he will face Hubert Hurkacz.
Alex de Minaur, another quarter-finalist at the U.S. Open, was knocked out by Dominik Koepfer with the German fighting back from a set down to win 3-6 6-3 7-6(5).
In the women’s draw, Angelique Kerber was knocked out in a 6-3 6-1 defeat to Czech Katerina Siniakova while Coco Gauf won her first ever match on clay.