The curse of the defending champion struck again for Daniil Medvedev.
The second-seeded Medvedev has never successfully defended a title and he failed again on Tuesday as he lost 6-1, 6-4 to American Tommy Paul to become the latest top player to crash out of the Italian Open.
“It's disappointing, to be honest,” said Medvedev, who has won 20 tour-level titles. "I wanted to do better here. I was not even close. What can I say? The more titles I win, the more chances I have to defend.
“So the more tournaments in a year I'm going to play where I already won, maybe not defend, but at least win twice the same tournament, that's what I'm going to try to do.”
The opener lasted just 28 minutes as the 14th-seeded Paul broke Medvedev on all three of his service games and then served out the set to love.
“Was a tough one. Mentally I had to be much better,” Medvedev said. “I started to calm myself down and focus on the match only at the end of the match, and it was too late. I had to do better. I was expecting myself to play better.”
Medvedev improved slightly in the second set when he broke immediately but Paul broke straight back and never looked back, securing his spot in the quarterfinals when Medvedev sent a backhand long.
The second-seeded Medvedev followed 10-time champion Rafael Nadal and top-ranked Novak Djokovic with early exits in Rome.
The only other players to have won the men's tournament at the Foro Italico in the past 19 years are Andy Murray and Alexander Zverev.
The third-seeded Zverev, who won in 2017, eased past Nuno Borges 6-2, 7-5 and will face Taylor Fritz.
Fritz reached the men's quarterfinals for the first time after recovering from losing a lengthy second-set tiebreaker — during which he let slip match point — to see off Grigor Dimitrov 6-2, 6-7 (11), 6-1.
Alejandro Tabilo backed up his stunning third-round win against Djokovic by edging Karen Khachanov 7-6 (5), 7-6 (10) to reach a Masters quarterfinal for the first time. He will face Zhang Zhizhen, who ousted Thiago Monteiro 7-6 (4), 6-3.
Paul will play Hubert Hurkacz after the seventh seed — who eliminated Nadal in the second round — beat Sebastian Baez 5-7, 7-6 (4), 6-4.
The other quarterfinal pits Stefanos Tsitsipas against Nicolas Jarry.