Juan Martin del Potro, pictured, faced Dominic Thiem in the fourth round of the US Open on Monday.
Juan Martin del Potro, pictured, faced Dominic Thiem in the fourth round of the US Open on Monday.
Al Bello/Getty Images North America/Getty Images
And when the injury hit del Potro called for the trainer after three games, things looked bleak for the 2009 winner.
And when the injury hit del Potro called for the trainer after three games, things looked bleak for the 2009 winner.
KENA BETANCUR/AFP/AFP/Getty Images
But del Potro appeared unaffected while French Open semifinalist Thiem subsequently injured his knee.
But del Potro appeared unaffected while French Open semifinalist Thiem subsequently injured his knee.
EDUARDO MUNOZ ALVAREZ/AFP/AFP/Getty Images
Thiem had to retire trailing 6-3 3-2 and del Potro was into his first grand slam quarterfinal since 2013.
Thiem had to retire trailing 6-3 3-2 and del Potro was into his first grand slam quarterfinal since 2013.
Mike Hewitt/Getty Images North America/Getty Images
He next faces Stan Wawrinka. The twice grand slam winner -- who saved a match point in the third round -- defeated Illya Marchenko 6-4 6-1 6-7 (5-7) 6-3.
He next faces Stan Wawrinka. The twice grand slam winner -- who saved a match point in the third round -- defeated Illya Marchenko 6-4 6-1 6-7 (5-7) 6-3.
TIMOTHY A. CLARY/AFP/AFP/Getty Images
Elsewhere, Karolina Pliskova saved a match point to beat Venus Williams 4-6 6-4 7-6 (7-3) to make a first major quarterfinal.
Elsewhere, Karolina Pliskova saved a match point to beat Venus Williams 4-6 6-4 7-6 (7-3) to make a first major quarterfinal.
EDUARDO MUNOZ ALVAREZ/AFP/AFP/Getty Images
Williams, who won the last of her seven majors in 2008, held the match point at 5-4 in the third on the Pliskova serve. Pliskova saved it with a gutsy swinging volley.
Williams, who won the last of her seven majors in 2008, held the match point at 5-4 in the third on the Pliskova serve. Pliskova saved it with a gutsy swinging volley.
EDUARDO MUNOZ ALVAREZ/AFP/AFP/Getty Images
But there were no issues for her younger sister, Serena. The top seed crushed Yaroslava Shvedova 6-2 6-3 to record a leading 308th grand slam win.
But there were no issues for her younger sister, Serena. The top seed crushed Yaroslava Shvedova 6-2 6-3 to record a leading 308th grand slam win.
EDUARDO MUNOZ ALVAREZ/AFP/AFP/Getty Images