Both men have planted their feet and are throwing baseline bombs.

Jo Wilfried Tsonga leaves the trench, but gets his range wrong, cuffing over the back to take it to deuce.

A corking serve though and a backhand dumped into the net from Kyrgios mean we are heading back to tie-break town.

Massive clubbing forehand power from both ends of the court.

Jo-Wilfried Tsonga finds the firepower to pierce Nick Krygios defences and nip back to 30-15.

Ooohhh! Double fault and 30-30. Teeter, totter. How are those nerves Nick.

He squanders his last challenge of the set on another Hawkeye chasing a wayward first serve.

Pressure on.

A rocket 122mph second serve lands to a squeal of delight.

A blistering ace.

Pressure off.

Jo-Wilfried Tsonga pings a winner out of the heart of the strings to move within a break of taking the set and levelling up the match.

Image source, EPA

A titanic tussle, seismic shot-making and a cauldron of heat and excitement.

You've come to the right place.

Kyrgios hangs tough under pressure to hold from deuce.

Estonia's Anett Kontaveit, seeded 32nd, is taking it to Jelena Ostapenko.

French Open champion Ostapenko has won only 10 of 32 points on serve and is wobbling badly at a set down.

Image source, Getty Images

Tsonga plays an unbelievable return, the ball is called long - and Kyrgios just turns to him and tells him to challenge it!

Tsonga, massive grin on his face, shakes his head at Kyrgios, thinking he's winding him up. He wasn't, though! It was in, and he and Kyrgios share a grin.

A very tidy hold for the Frenchman.

Image source, Getty Images

Over on the Margaret Court Arena, French Open champion Jelena Ostapenko has lost all four of her opening service games.

Estonian Anett Kontaveit has not been much better, but she is one game away from taking the opening set - however it arrives.

An ace from Kyrgios is followed up by a divine winner, right into the corner of the court, from Tsonga.

Kyrgios is irked as he swipes a forehand into the net at the last second, bringing the scores to 30-30, but Tsonga spoons his reply out.

Oh! A nothing sort of drop shot from Kyrgios draws Tsonga up to the net - and he slaps his backhand over the baseine!

Tsonga takes an impromptu snack break during the changeover.

I'm going to follow his lead.

Kyrgios meets a fine lob from Tsonga with that between the legs shot, and Tsonga watches it bounce out.

Another entertaining game, book-ended by aces from Tsonga, who holds.

Image source, Getty Images

David Law
Radio 5 live sports extra commentator at Melbourne Park

This is what we were after. This match is crackling now. It is just blow and counter-blow from two giants of the game and the crowd are fully locked in.

Listen in to the 5 live commentary via the link at the top of this page.

And breathe...

This feels properly feisty now.

Both players are putting their all in. It's Kyrgios who comes off the better, though, first with a big serve and then a forehand swipe to hold.

Tsonga, somehow, manages to get racquet on a backhand volley and a kind bobble off the net goes his way.

A little loopy on the backhand from Tsonga and it's called out. Kyrgios mimes to him it's a 50-50 call and he should probably challenge it, which Tsonga does - and it's in! I'm a fan of that.

A hot dog from Kyrgios is met by Tsonga for 30-30, before Kyrgios coughs up his first double fault of the match!

An almighty slash from a pumped-up Kyrgios will force it to deuce. What a shot!

Tsonga has another word with the umpire - he says that someone in the crowd spoke to him and it put him off.

The umpire tells him he can't respond and Tsonga asks why he can't say what he wants. Hmm.

Here's Kyrgios to serve.

* denotes next server

Image source, Getty

We're not at deuce for long, as Kyrgios flashes a forehand into the net.

And Tsonga holds with an ace! He looks a touch happier out there now.

Double fault from Tsonga! Tsonga went for a huge second serve - not realising it was his second serve - and fluffed it.

Advantage Kyrgios, but Tsonga saves it with a delicious swipe. Kyrgios challenges the call of in, although he seems to know it's not going to go his way.

Lovely. A shimmy of the feet from Tsonga and he rattles a forehand past Kyrgios.

And the second break point goes begging! Saved with a smash at the net. Deuce.

Tsonga received a code violation for that outburst - he was looking towards the crowd beforehand, but I'm not entirely sure what it was about.

Whatever happens, it's rattled him. Kyrgios is all over him in this service game and two break points come rattling along...

A very unhappy Tsonga can't get back into his groove, and Kyrgios batters serve and seve through him.

An easy love hold for Kyrgios.