Novak Djokovic once again benefited from an injured opponent at the US Open as a hamstring injury forced Mikhail Youzhny to retire with the score just 4-2 in the first set of their third-round match
World number one and reigning champion Djokovic was given a walkover against Jiri Vesely in the second round after the Czech withdrew due to pain in his forearm, and a similar situation resulted in his progression to the last 16.
The Serbian has been struggling with a right arm injury himself and had to take a medical timeout during his first-round win over Jerzy Janowicz.
The walkover against Vesely provided him with extra time to recover, and the benefit showed early on as he entered into a long rally with Youzhny in game two.
Although Djokovic lost that point to a brilliant backhand down the line from the 34-year-old Russian, it showed a glimpse of a return of a return to his best tennis after disappointment at Wimbledon and the Olympic Games.
Youzhny called for his trainer when trailing 3-1 and took a medical timeout at the end of the next game, continuing after having his left upper leg strapped.
The Russian returned to the court and managed to hold serve, but the strain proved too much and he retired to jeers from the stands.
Djokovic now has more time to recuperate ahead of attempting to book a place in the quarter-finals.
"I don't think I ever had this situation in my career... obviously I wish Mikhail a speedy recovery. I think he carried the injury into this match, that's what he said," Djokovic said in his post-match interview.
"I'll try to get the positives out of these six games. I did start with good intensity so I'll try to carry this into the next round."