In-form 19-time grand slam champion, Roger Federer has survived a topsy-turvy five-set match with American teenager, Fraces Tiafoe to advance to the second round at Flushing Meadows.
Federer eventually prevailed 4-6, 6-2, 6-1, 1-6, 6-4 to set up a meeting with either Mikhail Youzhny or Blaz Kavcic.
Tiafoe, 19, stunned Federer in the opening set, breaking early, before claiming it 6-4. Federer then turned things around, claiming the ascendancy in the next two sets, before Tiafoe showed plenty of fight to level it at two sets all.
Federer hit an uncharacteristically high 56 unforced errors, compared to just 41 winners.
Meanwhile, the defending champion on the women's side, Angelique Kerber, has been bundled out in the first round, going down 6-3, 6-1 to teenager, Naomi Osaka.
Kerber struggled with Osaka's shot making and power, as the Japanese youngster belted 22 winners to Kerber's nine. It is only the third time in US Open history a defending champion has been bundled out in the first round.