Ahead of the 2016 U.S. Open, the final Grand Slam tennis tournament of the season, the speculation was essentially whether or not Andy Murray could prevail over Novak Djokovic.

Even though Djokovic fell on his face at Wimbledon and also made an early exit in the Rio di Janeiro Olympic Games, there was never any doubt that he has been, is, and will be the world’s number one ranked player.

So formidable is he that his opponents in the U.S. Open are surrendering early, rather than face a somewhat prolonged defeat.

Djokovic’s third-round opponent, Mikhail Youzhny, was only willing to play six games before he called time due to an injury.

Djokovic’s second-round opponent, Jiri Vesely, scratched a couple of hours before the match due to an inflamed forearm.

This is the 10th consecutive year Djokovic has made it into the fourth round and the final 16. He won in 2011 and 2015, and had legitimate calendar-year Grand Slam aspirations after winning the Australian Open for the sixth time and finally breaking through in the French Open for the first time.

Djokovic played his way into the semifinals with a rather easy victory of Kyle Edmund, who won only seven games and spent less than two hours on the main stage.