After surviving a tough match against Alex De Minaur in the fourth round at Wimbledon, Novak Djokovic had a funny reason why Monday's win meant more to him.

The now-retired Federer sat in the Royal Box for his former rival Novak Djokovic's 1-6, 6-4, 6-4, 6-4 victory over Alex de Minaur in the fourth round at the All England Club.

The win marked the 16th time Djokovic has moved into the quarterfinals at Wimbledon. The event has been his second-best Grand Slam over his career. Djokovic has seven wins at Wimbledon, and has played in the final at the event in each of the last six Wimbledons.