World No.1 Novak Djokovic reached his 10th French Open semi-final but suffered an injury scare before beating Spain’s Pablo Carreno Busta 4-6 6-2 6-3 6-4 on Wednesday.

A month after being defaulted for striking a line judge with a ball while playing Carreno Busta in the US Open fourth round, the 33-year-old Serbian found himself in trouble once again.

This time it was nothing more sinister than pains in his neck and arm as Djokovic lost the opening set to the 17th seed – the first one he has dropped in the tournament.

Djokovic looked flat and had to save break points early in the second set before raising his game to level the match.

It looked plain sailing when he led 3-0 in the third set before a dip allowed Carreno Busta back but Djokovic saved a break point at 3-3 before pulling away.

Djokovic, bidding for a second French Open crown, produced several loud roars as he tried to fire himself up.

Carreno Busta hung on gamely but Djokovic was superior in the big moments and one break in the fourth was enough to set up a semi-final clash with Stefanos Tsitsipas.

The Greek produced a clinical performance to storm into the semi-finals with a 7-5 6-2 6-3 victory over Andrey Rublev.

Tsitsipas’s only moments of concern came in the opening set when Russian Rublev, the 13th seed, made a brisk opening to lead 5-3.

Yet four games later, Rublev had surrendered the set, and barely more than an hour later, he had lost the match, winning only five more games in what proved a one-sided encounter with the No.5 seed.

“I’ve been feeling really comfortable on this court and despite a bad start and being a break down I remembered what a big fighter I am,” Tsitsipas told the sparse crowd on Court Philippe Chatrier afterwards.

“It’s about fighting and trying to find solutions at difficult moments. I managed to get my brain working and found solutions.

“Roland Garros is a tournament I have been watching since I was a kid and always dreamed of playing on these courts.

“I used to skip classes at school to watch it. That’s how much I like this tournament. It’s a dream come true playing here and in front of the public.”

Tsitsipas had led by two sets and 5-1 only to lose to Borna Coric at the US Open last month, and just last Sunday in the Hamburg final he served at 5-3 up in the deciding set against Rublev, only to lose it 7-5.

There was no such drama here, though, as the 22-year-old held to love, finishing Rublev off with a volley at the net to reach his second grand slam semi-final and his first in Paris.