2021-10-28 22:15:34 GMT+00:00 - After falling behind 3-0 in the deciding set, American qualifier Frances Tiafoe battled back to take down No. 1 seed Stefanos Tsitsipas of Greece 3-6, 6-3, 6-4 Thursday in the second round of the Erste Bank Open in Vienna, Austria. Tiafoe saved three of four break points in the third set and broke Tsitsipas" serve twice en route to winning five straight games to make it 5-3. Tsitsipas smashed 11 aces in the match but committed six double faults along the way. It"s the second time in three meetings this year that Tiafoe took down his higher-ranked rival; he won in straight sets in the first round at Wimbledon before Tsitsipas got revenge at the Tokyo Olympics. Five other seeded players won their second-round matches, but four needed all three sets, including German No. 2 seed Alexander Zverev against Australia"s Alex de Minaur; Norwegian fourth seed Casper Ruud against Italy"s Lorenzo Sonego; Canadian sixth seed Felix Auger-Aliassime against Cameron Norrie of Great Britain; and No. 8 seed Diego Schwartzman of Argentina against France"s Gael Monfils. In the quarterfinals, Schwartzman will draw Tiafoe while Zverev will meet Auger-Aliassime. St. Petersburg Open Australia"s John Millman withstood eight aces from his opponent and won a 6-3, 6-2 decision over Russian fourth seed Aslan Karatsev in the second round at St. Petersburg, Russia. Millman saved all four break points he faced while Karatsev saved 10 of 12. Karatsev committed five double faults. Karatsev wasn"t the only Russian seeded player to lose in front of the home crowd. Marin Cilic of Croatia defeated No. 6 seed Karen Khachanov 6-4, 6-7 (1), 6-4. No. 3 seed Roberto Bautista Agut of Spain needed only 78 minutes to beat American Mackenzie McDonald 6-3, 6-2. In a duel between two Americans, No. 5 seed Taylor Fritz took down Tommy Paul 7-6 (3), 6-4, while No. 8 seed Sebastian Korda of the U.S. lost to Botic van de Zandschulp of the Netherlands 6-2, 7-5.