Swiss 23rd seed and 2016 winner Wawrinka headed Djokovic 6-4, 7-5, 2-1 if the Serb stopped, having received treatment on his troublesome left shoulder before the beginning of the third group.
“It is never how you wish to complete a game. I am sorry for Novak. He is a wonderful winner,” Wawrinka explained.
He said that he felt”virtually pain-free” after a straight-sets defeat of Denis Kudla in round three, but the issue resurfaced against Wawrinka at the initial meeting between the group because of the closing three decades back.
“I wish to maintain my degree tonight. I believe I had been playing super excellent tennis. I am pleased to return,” explained Wawrinka, that will meet fifth seed Daniil Medvedev from the quarter-finals.
“It helped me significant time understanding I have the match to beat him on this court.
“I had been feeling great. As soon as I came to the clinic here, I was going nicely, playing nicely. I was very confident with the amount I’d, but you will never know when you’re playing with the number one player on earth.”