Novak Djokovic said his victory over Felix Auger-Aliassime in the last eight at Wimbledon was "as good as a final", having teed up a semi-final clash with Jannik Sinner.

Djokovic kept his bid for a record-breaking 25th grand slam crown alive by coming through a five-set thriller on Tuesday, triumphing 7-6 (12-10) 3-6 6-3 6-7 (4-7) 7-6 (10-4).

It was Djokovic's 50th five-setter at a major, the most of any player in the Open Era, with the gruelling encounter lasting five hours and 14 minutes.

Aged 39 years and 38 days, he is the second-oldest man in the Open Era to reach the Wimbledon semi-finals, younger than only Ken Rosewall, who did so at the age of 39 years and 234 days in 1974. 

Asked if he was surprised by his level in his on-court interview, Djokovic said: "Yes and no.

"I guess yes, at this stage, that I'm still able to battle these young guys that have 15 years less than me, that I'm able to beat them by the tightest possible scoreline.

"In a sense, it is really a nice surprise. But at the same time, I always have the highest expectations for myself.

"I can be very self-critical, very hard on myself. But I try to enjoy the moments like this."

Djokovic will face the sternest of tests in the last four, though, as he takes on Sinner for the 12th time at ATP Tour-level.

Sinner currently leads their head-to-head 6-5.

Among the 36 players to have faced Djokovic at least 10 times at ATP level, Sinner is the only one to hold a positive record (Carlos Alcaraz has a 50% win rate).

But Djokovic is hopeful that Friday's titanic encounter will not be his final match at the All England Club.

"I don't know what tomorrow brings, but I still want to go at least one more step further," Djokovic said.

"But this was as good as a final for me. I gave it all that I had."

Djokovic lost to Sinner in straight sets in last year's Wimbledon semi-finals, with the Italian then going on to defeat Alcaraz in the final.

But the Serbian has progressed from 10 of his 14 semi-final matches at SW19, with his other defeats at that stage coming in 2007 (versus Rafael Nadal), 2010 (against Tomas Berdych and 2012 (to Roger Federer).