World number one Novak Djokovic had to work hard for a three-set victory over Hungarian Marton Fucsovics at the Paris Masters on Tuesday in his first match since losing the U.S. Open final in September.
Djokovic, who is tied with Roger Federer and Rafael Nadal on 20 major titles, came up short in his bid for a calendar Grand Slam at the U.S. Open, losing in straight sets to Russian Daniil Medvedev at Flushing Meadows.
He showed signs of rustiness in the French capital on his return to action in the second round on Tuesday, after getting a first-round bye, eventually winning 6-2 4-6 6-3.
The first set was comfortable, and it looked like the Serbian would mark his return with a routine success, but Fucsovics rallied in the second, breaking twice to take the set.
World number one Djokovic looked to be in trouble in the deciding set, with Fucsovics playing the better tennis, but at 1-1, 30-30 the Serb won 10 points in a row to take charge of the match, finishing the contest with a forehand volley.
Looking for his sixth Paris Masters title, Djokovic will play either Adrian Mannarino or fellow Frenchman and 15th seed Gael Monfils in the last 16 after the latter came from a set down to beat Miomir Kecmanovic in the first round on Tuesday.
The year-end number one spot in the ATP rankings is based on results during the calendar season and Djokovic can seal it for the seventh time with a triumph in Paris.
"It was a great fight and a great opening match for me," he said. "I did not expect anything but I knew it was not going to be an easy match.
"I couldn't break his serve, he was playing with a lot of precision and we pushed each other to the limit."
In other first-round matches, Bulgarian Grigor Dimitrov beat Frenchman Richard Gasquet in three sets, while Australian number two, James Duckworth, progressed with an impressive victory against world number 20 Roberto Bautista Agut, also in three sets.