No. 20 seed Diego Schwartzman ousted the sixth seed Alexander Zverev 3-6, 6-2, 6-4, 6-3 to reach his second US Open quarter-final here in three years. The Argentine, who made it to this round without dropping a set, played steady tennis throughout to tie the biggest win of his career by ATP Ranking (No. 6) after three hours and eight minutes.

Source:: https://www.atptour.com/en/news/schwartzman-zverev-us-open-2019-r4