World No. 1 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 break points 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 defeat by Djokovic in the last four of the Australian Open.