(Reuters) - Italian teenager Jannik Sinner has never reached the quarter-finals of a Grand Slam before and the 19-year-old will have the sternest test of his fledgling career when he takes on sixth seed Alexander Zverev at the French Open on Sunday.
Having upset 11th seed David Goffin in the first round, Sinner, last year's NextGen ATP Finals champion, has come to grips with the slow claycourts this year to mount a serious challenge.
His run follows some notable results in the clay swing that began last month, including a famous victory over world number six Stefanos Tsitsipas in Rome.
Sinner, however, was very blunt in his self-assessment, stating that he still needed to improve in best-of-five-sets matches despite having not yet dropped a set.
"I wish I would be like that. I wish I would win every match in three sets, then I wouldn't need to play five sets as well," Zverev, who has already dropped two sets at Roland Garros, said.
"Sometimes you have to dig deep. He's young. I've been at his age, where he is at now, I know. Physically, he probably still needs to improve. Tennis-wise...he's playing absolutely great."
Zverev has won all six of his matches that have gone to a decider in Paris and six of his last seven anywhere, with that one loss coming in a painful defeat to Dominic Thiem in last month's U.S. Open final.
Having also reached the semi-finals in Australia, the 23-year-old German is seeking to cap his most successful year in the majors by annexing a maiden Grand Slam title.
In Sunday's other matches, women's top seed Simona Halep takes on Polish teenager Iga Swiatek while third seed Elina Svitolina goes toe-to-toe with local hope Caroline Garcia.
Rafa Nadal continues his pursuit of a record-extending 13th title at Roland Garros when he faces 20-year-old American Sebastian Korda.
The son of Petr Korda, the 1998 Australian Open champion and 1992 Roland Garros finalist, underlined his genuine promise when he saw off big-serving compatriot John Isner in the second round.
(Reporting by Rohith Nair in Bengaluru; editing by Ian Chadband)