Novak Djokovic is through to the fourth round of the French Open after surviving a scare against unseeded Argentine Diego Schwartzman.The Serbian was booed at Roland Garros due to smashing his racket into the ground after sending one of his shots into the net during the third set.The world number two was out of sorts for much of the match, hitting an unprecedented 21 errors and letting a 4-1 lead in the first set go.The 30-year-old’s game improved, however, with the arrival of his new coach Andre Agassi midway through the second set.Djokovic spoke after the mammoth five set test, and told journalists that Agassi’s arrival to the court inspired him to break Argentine Schwartzman’s serve."I was focused on the screen and I saw obviously people reacting when he arrived."He was not supposed to be here today, because we have finished yesterday with our in-person collaboration here in Paris."I appreciate that. I respect that very much that he managed to do things and move his commitments around so he could come and watch."The newly revitalised Djokovic broke the Argentine's serve late in the second set, and in days gone by, the 30-year-old would have used that as a platform to take the match away from his opponent – Schwartzman had other ideas.The 24-year-old from Buenos Aires had never been to the third round of a major Grand Slam tournament and he broke Djokovic’s serve for a 5-3 lead and then won the final game 0-40 to see out the set.The Rolando Garros crowd were enraptured by the match and many were excited about the possibility of an upset. But Djokovic is not a 12-time Grand Slam winner for nothing, and the Serb changed tactics, quickening the pace of the match and shorting the rallies.The pressure was clearly starting to tell for Djokovic. The 30-year-old was 4-0 up in the fourth set and really did not need to start arguing with umpire Ramos after he received two warnings for his conduct on the court.You can see his racket incident which led to fans booing him in the video below.

Once the world number two calmed himself down, he won 12 of the last 14 games winning the match before the ominous dark clouds hanging over Roland Garros could affect the match.

"Playing a five-setter at this stage is good,

"I enjoyed playing, really, even though of course at times I was not playing my best, especially for first three sets, but fourth and fifth sets went completely my way." Djokovic concluded.

The Serb will play Spaniard Albert Ramos in the fourth round tomorrow with the match starting at 10:00.