Novak Djokovic overcame a difficult opening test to beat Valentin Vacherot 6-7 (5), 7-5, 6-1 on Tuesday, keeping his ATP Finals qualification hopes alive with a comeback victory at the Paris Masters.
The 39-year-old Serbian, a record seven-time champion in Paris, became the oldest player to win a match in the tournament's history after recovering from a set down against the in-form Monegasque.
The victory marked Djokovic's first win at an ATP Masters 1000 event since reaching the fourth round at Indian Wells in March. He is also chasing his 103rd career title, which would draw him level with Roger Federer in second place on the all-time list, behind Jimmy Connors' 109.
Djokovic faced a difficult challenge against Vacherot, who arrived in Paris after winning the Swiss Indoors in Basel on Sunday. The 27-year-old had also beaten the Serbian in last year's Shanghai Masters semifinals before going on to claim the title.
Vacherot again troubled the former world No. 1 with his powerful serve, firing 22 aces to take the opening set. After an evenly contested start, the Monegasque recovered from a 5-4 deficit in the tiebreak, winning four consecutive points to secure the advantage.
Djokovic's difficulties continued in the second set as he dropped serve early. The Serbian requested a medical timeout for treatment on his right shoulder while trailing 2-1, but quickly recovered the break after Vacherot misjudged a routine return.
The Monegasque also required treatment for an ankle problem as the match intensified.
Djokovic faced another scare while serving at 4-4, saving three break points to prevent his opponent from moving within a game of victory. He then struck in the 12th game, breaking Vacherot to level the match and force a decider.
The Serbian took control in the third set, breaking early and using his experience to dominate the rallies. He eventually completed the comeback in two hours and 35 minutes with a powerful backhand winner down the line.
"I expected a match like this, to be honest, with very few opportunities to break for me," Djokovic said.
"He has a tremendous serve. It is huge, both first and second. For a set and a half, I had difficulty reading his serve, and even if I guessed right, it was coming with some speed."
Djokovic admitted the contest had taken a physical toll but was pleased with his response.
"The third set was really good but very tiring physically, a lot of long rallies," he said. "I am still there, still hanging on and still giving it whatever I can, trying to find my best level when it matters."
The victory kept Djokovic in contention for a place at the ATP Finals, scheduled for Nov. 15-22 in Turin.
He currently sits 11th in the ATP Live Race to Turin and needs a strong run in Paris to improve his chances of reaching the eight-man season-ending tournament. Zverev, Carlos Alcaraz, Ben Shelton and Daniil Medvedev have already qualified.
Djokovic, who missed the previous two editions through injury, will next face Australia's Rinky Hijikata.
Shelton advances, Rune eliminated
Third seed Ben Shelton opened his campaign with a comfortable 6-3, 6-4 victory over Britain's Cameron Norrie in 71 minutes.
The American, who received a first-round bye, extended his season tally to 42 victories. Despite dropping serve late in the second set, he immediately recovered the break to close out the match.
Shelton has already qualified for the ATP Finals and recently added former Alcaraz coach Juan Carlos Ferrero to his team for the 2027 season.
His victory was followed by a ceremony honouring French veteran Gael Monfils, who retired last month at the age of 40.
Elsewhere, 2022 champion Holger Rune suffered a first-round exit, losing 7-5, 6-4 to 12th seed Tommy Paul. The Dane is still working his way back from an Achilles injury that kept him out of action for an extended period.
Matteo Berrettini defeated 14th seed Brandon Nakashima 6-4, 3-6, 7-6 (10-8), while Taylor Fritz recovered from a set down to beat Benjamin Bonzi 3-6, 6-3, 6-4.
French teenager Moise Kouame lost 6-3, 6-1 to lucky loser Nuno Borges, while Casper Ruud defeated rising Spanish player Rafael Jodar in straight sets. Jodar's elimination secured Italy's Flavio Cobolli a place at the ATP Finals despite his withdrawal from Paris because of a leg injury.
World No. 1 Alexander Zverev and second seed Alcaraz begin their campaigns Wednesday. Zverev faces Lorenzo Musetti, while Alcaraz takes on Alex Michelsen.