PARIS -- Stefanos Tsitsipas was in a reflective mood after beating Zhang Zhizhen 6-3, 6-3, 6-1 to reach the fourth round of the French Open on Friday.
The 2021 runner-up says tennis plays a fundamental part in shaping his thinking.
"I get the feeling that without tennis my life would have been so much different, with regards to challenging myself and setting personal goals for myself," Tsitsipas said. "Tennis helps me fill out those dreams and fulfil my deepest desires as a human being."
The ninth-seeded Tsitsipas, who won the Monte Carlo Masters in April, feels his game is in good shape.
Next up for the big-serving Greek is unseeded Italian player Matteo Arnaldi.
"I have been keeping an eye on him the last six months," Tsitsipas said. "He's a very good fighter."
Arnaldi advanced by eliminating sixth-seeded Andrey Rublev 7-6 (6), 6-2, 6-4.
Rublev came as a contender after winning the Madrid Open this month but he showed frustration against Arnaldi for his lack of precision, committing 37 unforced errors and four double faults. After netting a forehand in the third set, Rublev smashed his racket on his knee four times.
"I am completely disappointed with myself, with the way I behaved, the way I performed, and I can't remember ever behaving worse in a Grand Slam tournament," he said. "It was the first time I ever behaved that badly."
Arnaldi disagreed.
"He does those things almost every match. Personally, I don't pay too much attention," Arnaldi said. "But it definitely does give me a little confidence, because it means I am giving him trouble, and what I was doing was working."
No. 2 Jannik Sinner of Italy progressed by downing Pavel Kotov 6-4, 6-4, 6-4. The Australian Open champion next faces Frenchman Corentin Moutet.
Two-time major winner Carlos Alcaraz also advanced after beating 27th-seeded American Sebastian Korda 6-4, 7-6 (5), 6-3. Alcaraz was a semifinalist last year at Roland Garros, losing to Novak Djokovic.