Top-ranked defending champion Novak Djokovic retired from his US Open match Sunday after dropping the first two sets to Stan Wawrinka, sending the Swiss three-time Grand Slam champion into the quarter-finals.
Djokovic, who won four of the past five Slam crowns and 16 overall, was in pain from a nagging left shoulder injury while 34-year-old Wawrinka, who also beat Djokovic in the 2016 US Open final, showed himself a true title contender."It helped me big time knowing I have the game to beat him on that court," Wawrinka said.
"It's never the way you want to finish a match. I'm sorry for Novak. He's an amazing champion."
On a day when Roger Federer cruised into a quarter-final against Bulgaria's Grigor Dimitrov and Russian fifth seed Daniil Medvedev reached his first Slam quarter-final, Djokovic's shocker stole the show.
"It's frustrating. Very frustrating," Djokovic said. "Obviously not the first, not the last player to get injured and withdraw from one of the biggest events in sport."
Djokovic admitted he has been hurting for weeks without detailing how or when the injury took place.
"The pain was constant for weeks now, some days higher, some days with less intensity," Djokovic said. "Taking different stuff to kill the pain instantly. Sometimes it works. sometimes it doesn't.Federer, a five-time US Open champion with 20 Slam titles, advanced to the US Open quarter-finals for the 13th time by routing Belgian 15th seed David Goffin 6-2, 6-2, 6-0 in only 79 minutes.
"Sometimes these scores just happen," Federer said. "You catch a good day, the opponent doesn't, then things happen very quickly... I found my groove after a while and was able to roll really. Never looked back."