Novak Djokovic reached the Wimbledon quarter-finals for the 16th time, but it proved a hard day's work at his Centre Court office as he ground past Australian Alex de Minaur on Monday.

The 38-year-old started abysmally and lost the opening set in 31 minutes but eventually assumed control of a cagey battle to win 1-6 6-4 6-4 6-4 to keep alive his quest for an unprecedented 25th Grand Slam title.

With Roger Federer watching from the front row of the Royal Box, the player whose record eight men's titles Djokovic is trying to equal, the sixth seed's usually surgical game malfunctioned early on as he dropped serve three times.

The hustling and bustling De Minaur continued to cause Djokovic headaches with his shot-placement and movement but the Serb found his range to win the next two sets full of attritional baseline rallies.

Even then Djokovic looked like getting dragged into a fifth set as De Minaur jumped 4-1 ahead in the fourth and had a point for a 5-1 lead, but he slammed the door shut just in time, winning five games in a row to take his place in the last eight where he will face Italian 22nd seed Flavio Cabolli.

"I don't know how I'm feeling to be honest. I'm still trying to process the whole match and what happened on the court. It wasn't a great start for me, it was a great start for Alex," a weary Djokovic said on court.

"He was just managing the play better from the back of the court and I didn't have many solutions. I was very pleased to hang tough in the right moments and win this one."

Djokovic has now won 43 of his last 45 matches at Wimbledon and not since 2017 has he failed to reach the final.

The two losses were against Carlos Alcaraz in the last two finals, but for half an hour on Monday it looked as though Old Father Time might finally be catching up with him.

First meeting

Djokovic had never met the man nicknamed 'Demon' on a grass court after last year's quarter-final between them never happened when the Australian withdrew with a hip injury.

He predicted beforehand that the 26-year-old would be a handful on the surface, and he was proved right.

With a relaxed Federer watching in an immaculate blue suit and shades, Djokovic's game crumbled into a heap of double faults, errant forehands and clumsy footwork.

"Sometimes I wish I had a serve and volley, and a nice touch from the gentleman that's there. That would help," Djokovic said of his old rival after sealing his 101st Wimbledon win in a grinding three hours and 19 minutes.

"It's probably the first time he sees me and I win. The last two I lost. It's good to break the curse."

De Minaur's game plan seemed to be to drag Djokovic into cat-and-mouse rallies, and initially it worked.

But Djokovic rebooted his computer-like brain and chipped away at the Australian who must have believed he could snap his 10-match losing streak against top-10 players.

Djokovic won a 34-stroke rally early in the second set but with service breaks being traded like a plummeting stock and Federer heading off for afternoon tea he simply could not shake off the tenacious De Minaur.

Serving at 5-4, Djokovic had to save two break points before leveling the match. He looked more like his dominant best to control the third set and having not lost a two-sets-to-one lead since 2010 it seemed like victory was a formality.

There was another twist, though, and it was a mightily relieved Djokovic who closed out the win.