Monte Carlo: Novak Djokovic was made to sweat before struggling to victory 6-3, 3-6, 7-5 against Gilles Simon at Monte Carlo on Tuesday in his first clay court match of the season.
"It was a very difficult match, with many changes of momentum," the world number two Djokovic said. "It was very tiring for me, the first clay of the season.
"But this is the start of the Roland Garros build-up."
Monaco resident Djokovic was broken at 4-4 in the decider but then reeled off three straight games to snatch victory.
He has suffered a disjointed start to the season with patchy form while recently sitting out the Miami Masters due to an elbow injury.
Djokovic won the Monte Carlo Masters in 2013 and 2015 but has won only one tournament so far this season, the Qatar Open at the start of January.