By Martyn HermanLONDON (Reuters) -Novak Djokovic reached the Wimbledon quarter-finals for the 16th time but it proved a hard day's work at his Centre Court office as he ground past Australian Alex de Minaur on Monday.

Right before Wimbledon began, Novak Djokovic declared it was the tournament that gave him the best chance to claim an unprecedented 25th Grand Slam singles trophy. Made sense, really, given that he’s won seven titles there already and reached the past six finals.

Novak Djokovic may never quite know how he came through on Centre Court against Alex De Minaur, but the beauty of Grand Slam tennis is that he doesn’t need to know. His mind switches immediately to the Wimbledon quarter-finals, which he has reached for the 16th time.