Wow! What a response from Tsitsipas. He saves both break points with some superb serves and the right shots to follow them up... and repeats the trick to hold.

Image source, Getty Images

A big cheer from the Centre Court crowd who want more tennis for their money. It's a hold for Sonego, but Nadal still has the crucial break.

Kat Downes
Commentator on BBC Radio 5 live

I don't think there's a chance of these two going for a pint at the Dog and Fox in Wimbledon Village after this match.

John Lloyd
Former GB Davis Cup captain on BBC TV

Absolutely brilliant from Kyrgios. You could see when he went to hit that forehand he l knew it was a big point. He picked the right spot and bent it round.

Harry Poole
BBC Sport at Wimbledon

Nick Kyrgios skips away following that Stefanos Tsitsipas double fault.

The volume levels rise once more as Kyrgios sets up two break points.

There's a massive opportunity here, and it could be fatal for the Greek fourth seed.

Not the greatest time for Tsitsipas's serve to go missing, as he slumps to 0-30 with a double fault and he is soon in trouble at 15-40 thanks to some Kyrgios magic.

Roof closed and we're back in action on Centre Court. Rafael Nadal needs two more games.

Kyrgios can be brilliant at the net but he does throw in the odd duff volley and that gives Tsitsipas a sniff at 30-all.

There's a reason Tsitsipas has only had one break-point all match, though, because the Australian is serving brilliantly today. Two big deliveries get him out of trouble here and we are still on serve and dead level in set four.

Watch Australia's Nick Kyrgios' earlier outburst at a Court One umpire after a wrong call was made.

Here's some of the key points....

• Kyrgios, who chirped away at the umpire throughout the match, lost a tie-break in the first set
• The Australian was given a code violation for an obscenity, but won the next two sets
• In between all that, Tsitsipas was warned after firing a ball into the crowd, and his opponent called for him to be defaulted
• Then the frustrated Greek was warned again and deducted a point after hitting the ball towards spectators again
• It came down to a tense tie-break in the fourth set and Kyrgios prevailed

Image source, Getty Images

Tsitsipas is not just working harder than Kyrgios, he seems angrier too... it's a combination that means he hits the ball as hard as possible every time.

He holds, and forget what I just said because Kyrgios is off on another rant - complaining to his box about their lack of advice since the first set, I think. They are all looking down at their toes.

Defending champions Neal Skupski and Desirae Krawczyk close out the third set to advance to the second round of the mixed doubles.

The second seeds were made to work by Thanasi Kokkinakis and Asia Muhammad but recovered from the disappointment of losing a second-set tiebreak to win the third set and set up a match against Dutchman Matwe Middelkoop and Ellen Perez of Australia.

Sonia Oxley
BBC Sport at Wimbledon

Sonego got his wish - the roof is now being closed on Centre Court and we will get some better light in here.

Image source, BBC Sport

Kyrgios throws in a bit of everything here - an ace, a brilliant zinging forehand and a daft attempt at a half-volley on the base-line - on his way to 40-30 before another big serve sees him home.

Nadal gets another game on the board and, despite being only two games away from the victory, the tournament officials decide that it's time to close the roof and turn on the lights.

The Spaniard doesn't look too impressed, but we're going to have a bit of a break while the roof gets closed.

Sonia Oxley
BBC Sport at Wimbledon

Nadal must have something fun planned this evening - maybe he's heard it's worth getting over to Court One...

The Spaniard, renowned for taking his time between points, is getting through his games very quickly in this match.

Andrew Cotter
Tennis commentator on BBC TV

Kyrgios lost interest in that game. He just thought he'd had enough and Tsitsipas has got a bit of a spring in his step.

Going on his body language here, Kyrgios seems to have lost interest all of a sudden - but who knows what is going on inside his head.

He swats away at a couple of big Tsitsipas serves with no success and at 40-0 decides to try a drop-shot... let's just say it doesn't end well.

Kyrgios is fine, judging by his movement here. Tsitsipas cannot really get a bead on his first serve at the moment, and even a couple of overly-casual shots by Kyrgios is not enough to change that.

Neil Leverett: This has to be the most entertaining tennis match I’ve ever seen. Perhaps for all the wrong reasons. Just extraordinary.

Adam Kitchiner: Loving the kyrgios match . Great psychology, great tennis.