With the apocalyptic rain hammering down on Centre Court's closed roof for a good while, adding to the sense of jeopardy beneath, Novak Djokovic came through an awkward opening round against a drop-shotting, free-swinging Korean, Soonwoo Kwon. 

This is Djokovic's "childhood dream tournament". But this was a long way from being a dreamy start to the Fortnight for the No 1 seed and defending champion as he dropped the second set against the wonderfully irreverent world No.81, and was later a point from going a break down in the third set.

But, in the end, the Serbian figured out how to handle Kwon, progressing 6-3, 3-6, 6-3, 6-4, at which point sunshine, blue skies and some kind of normal service had returned to Wimbledon. 

For all the other turbulence in Djokovic's tennis life - with the uncertainty about which other Grand Slams he will be able to play - there is one constant: he keeps on winning matches on the Wimbledon grass.

You have to spool back to 2017, to his quarter-final against Czech Tomas Berdych, for the last time that Djokovic lost on these lawns.

"Credit to Kwon for playing some really high quality tennis - he deserves some applause. If he had broken me in the third set, this match could have gone a different way," said Djokovic.

A tricky first Monday shouldn't overly concern Djokovic, as he will doubtless recall how he dropped a set in his opening round last summer, against British wild card Jack Draper, and still went on win the title.

Victory put Djokovic one seventh of the way to snaffling what would be a fourth consecutive title at Wimbledon, and to equalling his boyhood idol Pete Sampras's achievement of seven Wimbledon titles, which would leave him one short of Roger Federer's record eight.

In beating Kwon, Djokovic set a record of his own, becoming the first player, man or woman, to win 80 matches at each of the Grand Slams. 

Unvaccinated against COVID-19, Djokovic wasn't able to compete at this year's Australian Open, and there is considerable doubt whether he will be allowed to compete at the US Open at the end of the summer, which puts extra emphasis on the Grand Slams he can play as he chases Rafael Nadal, who is now two Slams ahead on 22.

After Wimbledon, it's possible he might not play another Grand Slam until Roland-Garros.

It's one of the Wimbledon traditions that the gentlemen's singles defending champion opens the Centre Court programme on the first Monday.

And, as the players walked on, many in the crowd might have been thinking that it had also become a tradition that Djokovic wins his opening match here, as he has never lost in the first round.

But, as the match continued, there were moments when you doubted whether that record would continue. 

Playing a drop shot is always a smart move on a new grass court. But Kwon had more than one play at his disposal, crushing so many groundstrokes past Djokovic that the Centre Court crowd were wondering how he had never beaten a top 10 opponent.

Not for the first time, Djokovic didn't enter a warm-up tournament before The Championships, preferring to play himself into form at the Aorangi practice courts and with some exhibition matches.

And perhaps that made him a little more vulnerable.

Competing for the first time since he lost to Nadal in the quarter-finals of Roland-Garros, Djokovic had a slow start, going 1-3 down, but responded by winning the next five games to take the opening set.

Kwon wasn't going away, though. As any tennis player can tell you, serving for a set brings its own pressures. When you're serving against Djokovic on Centre Court, those pressures are magnified one hundred-fold.

But Kwon held it together, even dealing with a short interruption as a spectator had medical attention, to level the match at a set apiece.

Facing a break point at 2-2 in the third, life was looking a little dicey for Djokovic, but he got out of trouble with a 113mph second serve. He broke for 5-3, which was all he needed for the set.

While Djokovic didn't have everything his own way after that, he took the fourth set to go through.

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