NOVAK DJOKOVIC said he was trying to “stay alive” after battling through to the semi-finals of the Shanghai Masters today.

The 38-year-old is among those to have struggled with the hot and humid conditions this week but he remains on course for a first Masters 1000 title in nearly two years after beating Zizou Bergs 6-3 7-5.

Djokovic, the oldest man to reach the last eight at Masters level, had vomited and collapsed during his previous matches, and he again looked far from physically comfortable during draining rallies against Belgian Bergs.

But he managed to make it through this contest in straight sets, serving it out at the second time of asking.

Asked what it had taken him physically and mentally to reach the last four, he said: “Pretty much everything. I’m just trying to stay alive, to be honest, on the court.

“First encounter with Bergs, great guy, obviously a lot of firepower in his game. At times I just tried to play an extra ball in the court and make him miss the ball. That’s what happened.

“I should have closed out the match at 5-4, he played a good game. I was a little bit too passive. Just very challenging conditions these few weeks for all the players. I’m glad to overcome this hurdle.”

In the semi-finals, fourth seed Djokovic will take on the surprise package of the week, Monaco’s Valentin Vacherot, who at 204 in the world is the lowest-ranked man this century to make it this far at a Masters 1000 event.

Qualifier Vacherot took out his highest-ranked opponent yet in 10th seed Holger Rune, with the Dane stricken by cramp during the final stages of a 2-6 7-6 (4) 6-4 defeat.

Vacherot was watched by his cousin, France’s Arthur Rinderknech, who will try to join him in the last four when he faces Felix Auger-Aliassime tomorrow.

The victory ensured 26-year-old Vacherot will break into the top 100 for the first time, and he could not hold back tears at the end.

“It was just an unreal moment for me,” he said. “So much emotion. To get to share that with my coach, brother, my girlfriend, Arthur my cousin. There’s a few people with me here, and also ready tomorrow to cheer on Arthur.”