Incoming world number one Carlos Alcaraz suffered his first outing in a tournament since October when he was beaten by Hungarian qualifier Fabian Marozsan at the Italian Open in the last 32.
Spaniard Alcaraz, who will replace Novak Djokovic at the top of the standings after the event, lost 6-3 7-6 (7-4)
It was only the 20-year-old’s second defeat in 22 clay-court appearances in 2023.
Marozsan, ranked 135th, had never played in the main draw of an ATP Tour event until this week in Rome.
But the 23-year-old looked full of confidence and unfazed by his opponent, hitting 24 winners and only 13 unforced errors.
He will face Croatian Borna Coric in the fourth round after pulling off one of the ATP’s biggest upsets in recent years.
The second seed, Alcaraz, had won his last 12 matches on clay, having won comeback titles in Barcelona and Madrid, and is considered one of the favorites to win the French Open, which begins on May 28.
“He surprised me a lot, his level was really high and I’m sure he’ll break out of the top 100 soon,” Alcaraz said.
“I didn’t play very well but he played at a high level and I couldn’t keep up with him.”
Marozsan caused problems for Alcaraz, who made a number of unusual errors, with his powerful forehand and nice drop shots.
Alcaraz saved a break point at 5-5 in the second set, which would have left Marozsan serving for the match, and led 4-1 in the resulting tie-break.
It looked like the US Open champion might force a decider despite being second-best all round, but Marozsan remained calm and fought back winning the next six points.
“It’s not easy to say something. I’m very happy. It was my dream last night,” Marozsan told Amazon Prime.
“I tried to do something special, win a few games or a set and just beat world number one.
“I can’t believe it. Everything was perfect today.”