The 20-time Grand Slam winner, Rafael Nadal, next plays the 13th seed Canadian Denis Shapovalov for a place in the quarter-final.
Rafael Nadal has opened his attempt to win a 10th Italian Open title with a straight sets victory over teenager Jannik Sinner to advance to the third round.
The 20-time Grand Slam winner won through 7-5, 6-4 in two-hours 10-minutes to bring his record to 16-1 in his opening matches in the Foro Italico.
His 18th-ranked Italian opponent had dug deep to try and pull off an upset, saving six set points in the first set in which he had been twice a break up.
Sinner was again a break up in the second before Nadal powered back for 4-4 seeing off the 19-year-old on his fourth match point.
"After Madrid it was important to start with a positive feeling," said Nadal, who was beaten in the last eight at both previous Masters events, in Monte Carlo and Madrid.
"Today was a tough match. I think I did a lot of things well. I made mistakes too but combined these with positive things too."
Nadal, 34, next plays Canadian Denis Shapovalov, the 13th seed, for a place in the quarter-final.
Tough loss for Sinner at home
Top seed Novak Djokovic and second seed Nadal have accounted for 14 of the past 16 titles at Foro Italico.
"It's a lesson that's tough to accept, " said Sinner, who also lost to Nadal in the quarter-final Roland Garros last year.
The teenager had been hoping to benefit from the presence of the home crowd in later rounds with a 25 percent capacity allowed from Thursday.
"It's tough to accept I'm already out.
"If I'd won today there would have been a bit of a crowd tomorrow and I love to play on front of the crowd. I'm disappointed and sad."
Only smiles when playing in Roma 😃🇮🇹 pic.twitter.com/SAP0HCz1B5— Jannik Sinner (@janniksin) May 11, 2021
Medvedev clay woes continue
Russian third seed Daniil Medvedev, who replaced Nadal this week as world number two, fell 6-2, 6-4 to 27th-ranked compatriot Aslan Karatsev in round two.
Medvedev also exited early in Madrid last week after pulling out of Monte Carlo after testing positive for Covid-19.
Karatsev, who won his first ATP title in Dubai in March, next plays American Reilly Opelka, ranked 47th, in the third round.
Austrian fourth seed Dominic Thiem rallied from a set down to battle past Hungary's Marton Fucsovics into the third round.
US Open champion Thiem, a semi-finalist in Madrid last week, won 3-6, 7-6 (7/5), 6-0 in 2hr 33min against 44th-ranked Fucsovics in the clay-court tournament which acts as a warm-up for the French Open.
Thiem, twice a runner-up at Roland Garros, will next play Italian Lorenzo Sonego who beat wildcard Gianluca Mager 6-4, 6-4.
"It was tough the whole match. I was struggling with the timing a little bit," said Thiem.
"I was fighting a lot with myself but kept fighting from the first to the last point. That paid off today, and I'm super happy about it."
Sixth seed Alexander Zverev of Germany, the 2017 Rome winner, eased past Bolivian Hugo Dellien 6-2, 6-2 to set up a third round meeting with Japan's Kei Nishikori.
Greek fifth seed Stefanos Tsitsipas advanced to a third round meeting with Italian ninth seed Matteo Berrettini.