Karolina Pliskova, Roger Federer advance to qurter-finals; Dominic Thiem, Elina Svitolina crash out

[caption id=“attachment_4011347” align=“alignnone” width=“940”]  Karolina Pliskova beat Jennifer Brady in the fourth round to keep her title challenge alive. AP[/caption] [caption id=“attachment_4011345” align=“alignnone” width=“940”]  Rafael Nadal won against Alexandr Dolgopolov to ensure a semi-final clash against Roger Federer is still on the cards. AP[/caption] [caption id=“attachment_4011343” align=“alignnone” width=“940”]  American ace CoCo Vandeweghe reacts after beating Lucie Safarova. AP[/caption] [caption id=“attachment_4011339” align=“alignnone” width=“940”]  Dominic Thiem went in as the favourite to win against Juan Martin del Potro in the fourth round. AP[/caption] [caption id=“attachment_4011341” align=“alignnone” width=“940”]  However, del Potro proved to be too good for Thiem as the Argentinian won in five sets. AP[/caption] [caption id=“attachment_4011337” align=“alignnone” width=“940”]  Roger Federer won comfortably against Philipp Kohlschreiber. AP[/caption] [caption id=“attachment_4011333” align=“alignnone” width=“940”]  Elina Svitolina was another top seed to crash out of the US Open. AP[/caption] [caption id=“attachment_4011335” align=“alignnone” width=“940”]  Madison Keys beat Elina 7-6 (2), 1-6, 6-4 to progress through to the next round. AP[/caption]