Melbourne, Jan 25 : Greek tennis player Stefanos Tsitsipas fought with his back against the wall to overcome American world No. 22 Taylor Fritz 4-6, 6-4, 4-6, 6-3, 6-4 in an Australian Open thriller to reach the quarterfinals here. Trailing by two-sets-to-one, the 23-year-old world No. 4 Tsitsipas' Australian Open hopes were hanging by a thread. But he raised his game in the fourth and fifth sets, slamming backhands and forehands through the Rod Laver Arena court to advance in three hours and 23 minutes. "I gave everything out on the court today," Tsitsipas was quoted as saying by atptour.com. "I am very proud of myself with the way I fought and the way I stay consistent in the crucial moments. I am overwhelmed. The stadium was on fire. It is too good to be true." Tsitsipas, who hit 53 winners and broke Fritz three times on his way to the last-eight, has reached the semifinals in Melbourne in 2019 and 2021. However, the eight-time tour-level champion has yet to capture a Grand Slam trophy, though he came close at the 2021 Roland Garros where he lost to Novak Djokovic in the final. The 23-year-old Tsitsipas will continue his bid to change that when he faces Jannik Sinner of Italy in the last eight after the 11th seed defeated Australian Alex de Minaur 7-6(3), 6-3, 6-4. With his victory, Tsitsipas now leads Fritz 3-0, and it is also the fifth time for the Greek to have advanced to the quarterfinals at a Slam. "I knew it was going to get physical and I kept reminding myself to get in there, do the work and not give up," Tsitsipas added. "Just a little more patience and at the end it paid off. It was good to have the crowd with me." World No. 2 Daniil Medvedev of Russia too reached the quarterfinals in Melbourne for the second time, surviving a serve-and-volley barrage from American Maxime Cressy, ultimately winning 6-2, 7-6(4), 6-7(4), 7-5 in three hours and 30 minutes. "He really did (serve and volley) well," Medvedev said. "First set I had control, but the second set I didn't manage to break him but won the tie-break and just wanted to continue this way. When I lost the third (set) and when I had eight break points in the fourth set, I was like, come on. Some of them I could have won, but he played well, but on the last one I played well." Medvedev is the fifth Russian man in the Open Era to reach the quarterfinals at the Australian Open on multiple occasions, joining Yevgeny Kafelnikov (5), Nikolay Davydenko (4), Aleksandar Metreveli (3) and Marat Safin (3). /IANS