World number one Novak Djokovic admitted he needs to work on his game ahead of next month’s French Open after he was knocked out by Aslan Karatsev in the Belgrade semi-finals on Saturday.
The 28th-ranked Karatsev saved 23 of 28 breakpoints to advance to his second final of the year following a 7-5, 4-6, 6-4 victory, gaining a measure of revenge for his…