No. 4 seed Stefanos Tsitsipas of Greece rallied Monday to reach the Australian Open quarterfinals in Melbourne. Tsitsipas survived a 4-6, 6-4, 4-6, 6-3, 6-4 thriller against American Taylor Fritz in three hours and 23 minutes. Monday's other fourth-round winners were No. 2 seed Daniil Medvedev of Russia, No. 9 Felix Auger-Aliassime of Canada and No. 11 Jannik Sinner of Italy. Tsitsipas struck 53 winners and 19 aces and