Novak Djokovic says he has room to improve despite easing past Taylor Fritz in straight sets to reach the semi-finals of the Paris Masters.
The world number one is competing in his first tournament since his dream of winning a calendar Grand Slam was ended by Daniil Medvedev in September's US Open final.
After beating Marton Fucsovics in three sets and then benefiting from a walkover against Gael Monfils in the last 16, Djokovic made light work of Fritz in Friday's quarter-final.
He sent down eight aces and was successful with 72 per cent of his first serves that landed on his way to a 6-4 6-3 victory.
However, Djokovic lost his serve on three occasions and, while happy with his overall display, the Serbian feels like there is more to come from his game in the French capital.
"I was absent from the tour for two months coming into this tournament," he said. "The last competitive match I played was in the US Open final, compared to the other guys playing one or two events prior to Paris.
"I knew that I needed to start well, with good intensity and put in a lot of hours on the practice court. But it's different when you play points in a competitive match.
"I am pleased with the way I played against Fucsovics and again today, though I did have ups and downs. I am not entirely pleased with the way I closed out the sets.
"I backed myself up with good returns and read Taylor's serve very well to get into rallies. I closed out the last couple of service games well and that's a positive."
Djokovic is aiming to win the Paris Masters for a record-extending sixth time in his bid to end the year as world number one for a record seventh occasion.
The Serbian will contest his 71st career Masters 1000 semi-final – four short of Rafael Nadal's record – against Hubert Hurkacz, who saw off James Duckworth 6-2 6-7 (4-7) 7-5.
With that victory, the world number 10 clinched the final singles spot at the ATP Finals in Turin later this month.
Hurkacz is the second Polish player to qualify for the event after Wojtek Fibak in 1976. It also means only European players will feature in the ATP and WTA Finals for the first time ever.
Saturday's other semi-final in Paris will be contested between Djokovic's US Open conqueror Medvedev and Olympic gold medallist Alexander Zverev.
Home favourite Hugo Gaston eliminated Pablo Carreno Busta earlier in the tournament but was always likely to face a tougher task against Medvedev.
So it proved, with the qualifier going down 7-6 (9-7) 6-4 in a match that saw Medvedev hit 13 aces to his opponent's one.
"When the atmosphere is against you, you need to face it," Medvedev said. "You need to try to win, no matter what.
"Even when it is against me, I think, 'I will try to beat my opponent and the crowd' because there is no other choice."
Zverev kept his momentum going with a 7-5 6-4 win over Casper Ruud in Friday's final contest, as he made it eight wins on the bounce.
The German held serve throughout, while breaking his opponent twice, to remain on course for a sixth final of 2021.