Six-time champion Novak Djokovic was stunned in straight sets by Hyeon Chung only hours after Tennys Sandgren upset No. 5 Dominic Thiem at the Australian Open.
The back-to-back upsets Monday have set up a very unexpected quarterfinal: Chung, the first South Korean to reach the last eight at a Grand Slam, versus 97th-ranked Sandgren, who had never won a match at a major or beaten a top-10 player until last week.
No. 58-ranked Chung relentlessly attacked Djokovic — who is playing his first tournament since Wimbledon last July because of an injured right elbow — in the 7-6 (4), 7-5, 7-6 (3) fourth-round win.
He ripped 47 winners, including a forehand on the slide and at...