Serbian tennis star Novak Djokovic secured a fighting win after being a set down in his round of 16 match at the ongoing Srpska Open to advance to the quarterfinal of the men's singles competition at the ATP 250 event on Wednesday.

The World Number 1 defeated the French teen Luca Van Assche 6-7(4), 6-3 and 6-2. After falling behind early in the third set, Djokovic recovered to win the two hours, 38 minutes-long match.

"It was not easy. This would probably rank as the slowest court, slowest conditions I have ever played in, to be honest. I could not penetrate through the court. I could not put any ball past him," said Djokovic as quoted by ATP.

Djokovic played with more depth and put his opponent's court coverage to the test, putting him on defence. The 35-year-old was aggressive on return, with a massively supporting crowd. He improved his season statistics to 17 wins and two losses.