Three-time champion Novak Djokovic kept up his quest for a record-breaking 25th Grand Slam title, battling past third seed Alexander Zverev 4-6 6-3 6-2 6-4 on Wednesday, to set up a French Open semi-final against top seed Jannik Sinner.

The 38-year-old Serbian notched his 101st victory at Roland Garros, site of his Olympic gold medal victory last year at the Paris Games, after three hours and 17 minutes. Former world number one Djokovic is just two matches away from becoming the first player, male or female, to win 25 Grand Slam singles trophies.

Earlier on Wednesday Sinner booked his spot in the last four with a straight-sets win over Kazakh Alexander Bublik.

"Obviously there was a lot of tension, pressure but it is normal when you play against Zverev, one of the best in the world, in the last five-six years," Djokovic said in a post-match interview.

"My game is based on a lot of running. I am 38 years old, it is not easy to keep running like that but, okay, it works." "A match like the one this evening is the biggest reason why I continue playing and competing at this level," he said.

Zverev, last year's finalist who is still searching for a maiden Grand Slam title, started out strongly and broke Djokovic in the very first game.

Attempting to join the Serb, Rafael Nadal and Roger Federer as the only men in the Open Era to reach French Open semi-finals in five consecutive years, the German held on to that advantage to earn the first set.

Knowing he could not match his 28-year-old opponent for fitness, Djokovic tried to keep the rallies as short as possible, playing more and more drop shots — 35 in total — to force the tall Zverev to the net.

Djokovic broke his opponent at 2-1 in the second set and was quickly 4-1 up before Zverev had any time to react. He secured the second set with yet another drop shot.