US Open 2017 round one: Alexander Zverez 7-6 7-5 6-4 Darian King.
Alexander Zverev came through a tricky clash with qualifier Darian King in straight sets after a tight late-night contest in round one of the US Open.
The much-fancied number four seed was far from his best as he edged past the plucky qualifier from Barbados 7-6 7-5 6-4 in just under three hours.
King was featuring in the main draw of a major for the first time, but the world number 168 more than rose to the occasion as he broke Zverev early on and repeatedly made life difficult for the German.
Zverev struggled to find the form that has seen him win two Masters titles so far this season, leaking errors and struggling on serve before taking a lengthy opener 11-9 in a rollercoaster of a tie break.
The second set saw fewer rallies to excite the crowd as both players began to find their rhythm on serve, with an improving Zverev making the decisive breakthrough in the 11th game.
One break was also enough in the third set as Zverev booked a place in round two against another 20-year-old starlet, Croatia's Borna Coric.