Djokovic through as Youzhny retires
Top seed Novak Djokovic cannot seem to get in a full match at the US Open, as the world No. 1 was given another rapid advance after Russian Mikhail Youzhny retired due to a leg injury when trailing 2-4 in the first set on Friday.
Youzhny was treated during the changeover at 1-4 in the third-round match and had his left thigh taped. He won the next game on serve but could not continue.
After receiving a walkover from Czech Jiri Vasely in the second round, Djokovic will next face 21-year-old Briton Kyle Edmund, who upset 20th seed American John Isner 6-4, 3-6, 6-2, 7-6 (7-5) with a quarter-final berth at stake.
Revitalised Konta through to last 16
Two days after collapsing in the New York heat en route to a three-set second-round victory, Britain's Johanna Konta reached the US Open round of 16 with no fuss.
The 13th-seeded Briton, who won her first WTA title in Stanford in July, overwhelmed 24th-seeded Swiss teenager Belinda Bencic 6-2, 6-1.
She will next play Anastasija Sevastova, the 48th-ranked Latvian who toppled French Open champion Garbine Muguruza before beating Kateryna Bondarenko 6-4, 6-1 in the third round.