Confident, composed and convincing — another clay-court Masters win now seems like business as usual for Zhang Zhizhen, as China's top ace continues to cement his elite status on the professional circuit.

Even with the majority of the crowd cheering against him at the Foro Italico, Zhang proved that he's the favorite on clay — even when facing a much higher-ranked opponent in Ben Shelton, the 2023 US Open semifinalist — after the Chinese world No 56 routed the 14th-ranked American power hitter in straight sets to advance into the fourth round of the ATP 1000 Rome Masters on Sunday.

A rare talent from China adapting particularly well to clay tennis, Zhang's round-of-16 appearance in Rome, the third time he's reached this stage of a top-flight Masters tournament, has maintained his feel-good momentum on the surface in recent years, sparked by a career-best quarterfinal run at last year's Madrid Masters.

Zhang attributed his fifth career win against a top-15 opponent to a solid pre-match preparation.

"Literally everything I'd prepared against him worked out today on court," Zhang said of his 6-2, 6-4 elimination of Shelton in just over an hour in the Italian capital.

"I watched his matches in Madrid this year and his performances when he reached the final in Houston. I anticipated his shots and returned his serves quite well.

"I am particularly happy with the fact that I managed to stay at a consistently high level all match long, without dropping my form to allow him any real chances (to come back). I had a great baseline game today, which gave me a huge advantage on clay," said Zhang, who will earn 88,440 euros ($95,280) in prize money for reaching the fourth round in Rome.

The Rome win also helped Zhang avenge a major loss to Shelton during their first and only previous encounter, when they met in the opening round at the 2023 Australian Open. The 21-year-old southpaw prevailed in a five-set thriller to deny Zhang a first main-draw win in Melbourne.

The rising American star, who is also improving his game on clay, highlighted by his first tour-level title in Houston, Texas, last month, found himself vulnerable to Zhang's almost flawless baseline game on Sunday, when the Chinese No 1 attacked Shelton's second serves aggressively, winning 58 percent of his points on the receiving end.

Although not serving well himself, Zhang's resilience, the quality and variety of his shots, as well as his footwork, carried him through, though, as he won 75 and 74 percent of points from his first and second serves, respectively, converting three out of eight break points to dictate the match.

Next up for Zhang will be Brazilian qualifier Thiago Monteiro, who's made an equally impressive run in Rome, overcoming former world No 6 Gael Monfils of France and world No 35, Australian Jordan Thompson, to reach the round of 16 for the first time in his career.

The Brazilian left-hander's recent surge on clay also includes an upset of world No 7 Stefanos Tsitsipas in the second round of last month's Madrid Masters.

Zhang revealed that he's approaching an unknown test against the Brazilian veteran, in a matchup that's long overdue.

"I don't know his game too much, but he should be in red-hot form now, having won a series of matches in Madrid and here," said the 27-year-old Shanghai native. He vividly remembers how he missed a much earlier encounter against Monteiro seven years ago.

In just his second year playing predominantly on the pro circuit, Zhang was drawn against Monteiro in a first-round qualifier at the 2017 ATP 250 Shenzhen Open, but later had to play his compatriot Bai Yan after Monteiro opted out of playing to compete in another Chinese tournament in Chengdu, where he made it directly to the main draw via ranking.

"Maybe he helped me reach my first career quarterfinal on the tour somehow," Zhang joked about the fact that he went all the way to the third round in Shenzhen that year without having to play the much higher-ranked Monteiro in the first qualifier.

Now, on the verge of cracking the world top 50 again, Zhang, who enjoyed his highest ranking at No 46 in February, said the open competition in Rome at this stage, following a series of injury-forced withdrawals and early exits of major stars, has raised everyone's ambitions, including his own.

"I've never considered that far to be honest," he said of the expectation of some fans for a run to the final. "Indeed, the draw looks quite even in my quarter, yet it means that every match from here will be a tough fight. No one is a clear-cut favorite and anyone can win."

"I will take it one match at a time, but if I have to set a target, I will set my sights on the semifinals," said Zhang, whose only other quarterfinal berth at a Masters was at his home hard-court tournament in Shanghai last year.