Novak Djokovic came from a set down to beat Jakub Mensik for a place in the Shanghai Masters semi-finals.

The fourth-seeded Djokovic came through 6-7 6-1 6-4 in two hours and 21 minutes against his Czech opponent, overcoming a deficit and a late injury scare around his left knee.

Djokovic will face Taylor Fritz in the last four on Saturday, live on Sky Sports, after the American beat David Goffin.

The 24-time Grand Slam winner appeared to be on course to take the first set when he claimed the first break of the match for a 5-4 lead, but Mensik hit straight back and forced a tie-break.

Djokovic went 3-0 up in the breaker, but Mensik showed impressive resolve to strike back and take it 7-4.

The Serb upped his level to dominate the second set before claiming a crucial break of serve in the decider to take a 3-2 lead.

There was brief concern as Djokovic repeatedly stretched out his left knee in the closing stages, but he produced a near-perfect service game to close out the match to love.

“We went toe to toe until the last moment, the last game,” Djokovic said. “I was fortunate to really find great serves in the last game, a couple of aces, that helps.

“I didn’t serve that well at the end of the first set when I was serving for the set at 5-4, he managed to turn things around. He played a good tie-break, I played quite a bad tie-break.

“I just kind of stayed collected and started off very well in the second. I felt that we both had a little bit of a physical crisis at the beginning of the second. I think we pushed each other a lot, a lot of long rallies, a tough battle.”

Fritz advanced to his fifth Masters semi-final with a straightforward 6-3 6-4 victory over Goffin of Belgium.

The 26-year-old was in control throughout the 82-minute encounter and converted three of his seven break points.

“I feel like sometimes it takes a couple of matches to find my routines, to find what feels good and what is working for me,” Fritz said.

“I feel like once I get past the first two rounds, I feel very locked in. I’ve come this far already, so I might as well really dial it in and I’m just enjoying being here.”

In the other semi-final on Saturday, top seed Jannik Sinner will face Tomas Machac, who toppled Carlos Alcaraz in the quarter-finals.

‘Part of me left with Nadal, Federer and Murray’

Djokovic was playing his first match since rival Rafael Nadal announced on Thursday that he will retire from tennis in November.

Djokovic holds a 31-29 head-to-head record against Nadal, who won 22 Grand Slam titles including 14 at the French Open,

The 38-year-old will make his final competitive appearance as Spain host the Davis Cup finals in Malaga next month.

Djokovic paid tribute to Nadal with a social media post on Thursday but spoke further on court following his match on Friday, also referencing the retirements of Roger Federer and Andy Murray.

“I meant every word. He’s been my greatest rival,” Djokovic said.

“The rivalry I had with him has impacted me the most in my career by far. We knew that moment is coming sooner than later, but it’s still a shock when it came officially.

“Also, for Roger a few years ago, and Andy as well this year. It’s a bit overwhelming for me, to be honest.

“I don’t know what to make out of it. I still enjoy competing but part of me left with them, a big part of me.

“It’s tough news for the tennis world, sports world. Rafa has been an inspiration, he is an inspiration to millions of children around the world. He can be very proud of his career.”

What’s coming up on Sky Sports Tennis in October?

• Shanghai Masters – ATP 1000 (October 2-13)
• Wuhan Open – WTA 1000 (October 7-13)
• Almaty Open, Kazakhstan – ATP 250 (October 14-20)
• Stockholm Open, Sweden – ATP 250 (October 14-20)
• European Open, Antwerp – ATP 250 (October 14-20)
• Japan Open, Osaka – WTA 250 (October 14-20)
• Ningbo Open, China – WTA 500 (October 14-20)
• Erste Bank Open, Vienna – ATP 500 (October 21-27)
• Swiss Indoors, Basel – ATP 500 (October 21-27)
• Guangzhou Open, China – WTA 250 (October 21-27)
• Toray Pan Pacific Open Tennis, Tokyo – WTA 500 (October 21-27)

Sky Sports+ has officially launched and will be integrated into Sky TV, streaming service NOW and the Sky Sports app, giving Sky Sports customers access to over 50 per cent more live sport this year at no extra cost. Find out more here.

Fabio Wardley’s huge rematch with Frazer Clarke is on the epic Artur Beterbiev vs Dmitry Bivol bill on Saturday October 12 live on Sky Sports Box Office. Book Wardley v Clarke 2 and Beterbiev v Bivol now!