Tennis-Djokovic grinds past Di Minaur to reach Wimbledon quarter-finals

By Martyn Herman LONDON (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. The 38-year-old started abysmally and lost the opening set in 31 minutes but eventually assumed control of a cagey battle to win 1-6 6-4 6-4 6-4 to keep alive his quest for an