The unseeded Aussie withstood 22 aces from the big-serving American and somehow broke his opponent's serve to prevail 7-6(2) 6-7(3) 6-3 in two hours and 31 minutes. Isner was unable to capitalize on his five break point opportunities, and records his first loss against Thompson, who next faces Italian Andreas Seppi in the quartferfinals.
Defending champion Reilly Opelka needed just an hour and 16 minutes to defeat Japan's Yoshihito Nishioka 6-4 6-4. The third-seeded American hit 20 aces and 72% of his first serves, saving all four break points faced. Surprisingly, this is Opelka's first win of the season, after losing in the first round in Adelaide and the Australian Open earlier this year.
Opelka faces 30-year old qualifier Jason Jung, who kept up his winning ways by defeating seventh seed Cameron Norrie 6-4 6-4 in an hour and 18 minutes. The Chinese Taipei native displayed speed and athleticism that allowed him to chase down every shot played by his British opponent.
Great Britain's Kyle Edmund defeated German Dominik Koepfer 6-2 6-4 in an hour and a half to advance to the quarterfinals. Edmund converted four break points and saved seven in the process, controlling the pace of the match from the baseline. He next faces unseeded South Korean qualifier Soonwoo Kwon, who upset second seed Milos Raonic in the previous round.