NEW YORK (CBS Sports/AP) — Roger Federer has been stunned in the U.S. Open’s fourth round by 55th-ranked John Millman of Australia 3-6, 7-5, 7-6 (7), 7-6 (3).

It’s the first time in Federer’s career that he has lost to a man ranked outside the top 50 at Flushing Meadows.

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The 20-time Grand Slam champion double-faulted 10 times, including twice in a row during the final tiebreaker.

Federer certainly had his chances to take control of the match, including two set points at 5-4, 40-15 in the second. He also blew a set point in the third.

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Millman will move on to the quarterfinals to face Novak Djokovic, who did his part Monday as he punched his ticket with a 6-3, 6-4, 6-3 win over unseeded Joao Sosa.

Djokovic, the No. 6 seed in the men’s draw, is 28-0 at the US Open when facing an opponent ranked outside the Top 50. Coming off his triumph at Wimbledon, he has reached the final eight at Flushing Meadows for the 11th time.

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(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)