After the 48th-ranked Tiafoe couldn't handle Wawrinka's fierce backhand passing shot, the two men hugged at the net. Now aged 38 and 34, respectively, Federer and Wawrinka teamed up to win doubles gold for Switzerland at the 2008 Beijing Olympics.
Wawrinka is playing Federer's hometown tournament for the 14th time. They have faced each other just once in Basel, in a 2011 semifinal won by Federer. Stefanos Tsitsipas and Roberto Bautista Agut advanced to their 13th quarterfinals in 2019, joint best on the tour.
The third-seeded Tsitsipas beat Ricardas Berankis 6-7 (4), 6-2, 6-4 and conceded just a single break point against the 70th-ranked Lithuanian. Earlier, fourth-seeded Bautista Agut won 6-2, 4-6, 6-3 against Richard Gasquet.
Hard-serving American Reilly Opelka upset sixth-seeded David Goffin 6-7 (4), 7-6 (4), 7-5 with the help of 29 aces. In the deciding set, Opelka used his one break point of the match to force the only service break in any of the five sets he has played in Basel this week.
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