Novak Djokovic was forced to come from a set down to beat Luca Van Assche 6-7 (4-7), 6-3, 6-2 in the Srpska Open second round on Wednesday.
Teenager Van Assche took a big step towards a stunning victory after going a set ahead, but the world number one rallied to seal his progression against the stubborn Frenchman.
Djokovic, who admitted his right elbow "was not in an ideal condition" earlier this week after a shock exit at the Monte Carlo Masters, was not at his brilliant self as Van Assche took the first set by finding two crucial breaks in the tie-break.
The Serbian improved, though, and he dominated the second set by holding all five of his service games and breaking twice to take the match to a decider.
With the first two games of the final set going against serve, Djokovic took over to win four of the next six and secure a comeback triumph.
Just over a month ahead of the French Open, Djokovic will be glad to have battled to victory in Banja Luka as he prepares for an attempt to win a record 23rd grand slam title at Roland Garros having already claimed the Australian Open crown earlier this year.
