Nick Kyrgios won his second match in the same day as he defeated Frances Tiafoe in the quarter-finals at the Citi Open 6-7 7-6 6-2 on Friday night.
Kyrgios had previously beaten Reilly Opelka after his tie was held back.
The Australian was almost equal to the young American's challenge in the first set but a double fault in the tie-break saw him fall behind.
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He almost went out in the second but a 14-12 slog in the decider saw him overcome five match points to level.
In a testy atmosphere - both players had words with the umpire over crowd behaviour - Kyrgios kept his focus and delivered 35 aces over the course of the match to win at 1am, which pushed back his doubles quarter-final to Saturday evening. 'I want to go to bed,' Kyrgios exclaimed before victory.
Kyrgios had earlier come flying out of the blocks to win his held over match against Opelka at the Citi Open.
The match was suspended on Thursday night due to the threat of stormy weather with Kyrgios winning 7-6(1) 2-1.
He made a quick start to break Opelka in the first game when the match resumed and went on to take three of the next four games in just 14 minutes to win the match 7-6(1) 6-2.
“0-30 doesn’t come up often against a big server like that so I knew I had to make every single ball and that’s what I did,” said Kyrgios after the match.
“I got a couple of second serve looks and put them in play, had to tough out some tough rallies but as I said, he’s got a great serve and he will have a hell of a career.”

First of two matches in one day for Kyrgios

Due to the rescheduling of the matches, Kyrgios will play his quarter-final later on Friday against Frances Tiafoe.
The Wimbledon finalist was also due to feature in the last eight of the men’s doubles in Washington, alongside partner Jack Sock. They were set to play French pair Edouard Roger-Vasselin and Nicolas Mahut after Kyrgios’ singles match, but Kyrgios' late finish on Friday saw it rearranged.
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