Novak Djokovic was rarely troubled in his defeat of Alejandro Davidovich Fokina, needing a little over an hour for a 6-2 6-1 win in the last 16 of ATP Rome.
The Spaniard initially impressed but was quickly worn down by the Serbian world number one. At 2-2 in the first set, he won nine games in a row in order to work towards victory, helped on his way by 30 unforced errors by his opponent, with crucial double faults setting him back.
The win means that Djokovic has set up a quarter-final against Stefanos Tsitsipas, who beat Matteo Berrettini 7-6(3) 6-2.
'Image not the best' - Nadal criticises Djokovic for 'strange' racket smash tantrum
- Halep suffers French Open scare as calf tear forces Rome withdrawal against Kerber
- Serena suffers shock loss in 1,000th match, Osaka also out
- Halep 'so disappointed' with injury blow - but will she make French Open?
Djokovic, a five-time Rome champion, performed in front of a crowd at 25 per cent capacity and believes he is steadily improving in the tournament.
"I thought I played well. He started well and broke my serve in the first game," Djokovic said. "I made some errors, but I managed to break back right away and establish the control and consistency on the court.
"I think from the back of the court I was just a bit more solid than him.
"He made some unforced errors and double faults in key moments, which obviously helped me get that necessary break forward.
I thought I played better, at least 20 or 30 per cent better, than I did against [Taylor] Fritz a few days ago. I am on a good trajectory and hopefully tomorrow will be even better.
Elsewhere, Reilly Opelka defeated Aslan Karatsev 7-6(8-6) 6-4.
Watch Murray and Djokovic train together in Rome
ATP Washington, DC
Djokovic can still complete the Grand Slam, says Nadal
'Dominant' - Emotional Zverev claims emphatic singles gold