Thiem gets the first serve in, Kyrgios sends a backhand into the net and it's match point Thiem after three hours 20 minutes.

Thiem was two sets down. He needs one point.

Thiem two points from the victory, but then hits a backhand long. 30-30.

A drop shot from Thiem wins the first point of what could be the last game of the match. But maybe the loudest roar of the night follows and that means Kyrgios is at 15-15.

Over on Rod Laver Arena, world number one Novak Djokovic is in control against Taylor Fritz now as the third set gets under way.

But the Serbian defending champion has not been finding it easy against the tenacious American and he celebrated wildly when he claimed that second set.

It's now or never for Nick Kyrgios. If he doesn't break Thiem's serve, he is out.

An ace from Kyrgios, serving to stay in the match, is very needed. Another follows seconds later and Kyrgios is still in this.

Thiem just now needs to hold his serve to set up a fourth-round match with Grigor Dimitrov.

Kyrgios misses a forehand and that gives Thiem three game points, but he only needs one with a drilled backhand. That seals the game. One more for Dominic and he advances. Nick needs perfection from now on.

Kyrgios can only net and Thiem looks up at his few supporters' in the players' box and pumps a fist. He was two sets down and in all kinds of trouble. Now he's 4-3 and a break up in the final set.

If he holds his serve twice he will be in the last 16.

But a backhand drifts wide from Kyrgios and that's a second break point for Thiem. This could be the match.

Thiem slides a backhand slice wide. Break point saved from Kyrgios. Five thousand fans in the John Cain Arena breathe again.

Thiem a brilliant backhand finds the corner. Break point Thiem. This is a huge, huge moment.

Kyrgios gets taken to 30-30, but a cross-court winner, just when he needed perfection, takes him to 40-30.

Any mistake now could be costly for either player.

A drop shot from Thiem brings us to deuce. Chance for the third seed.

Chris: Really intelligent play now by kyrgios, not going for the aces, making sure his first serves are strong enough to get the advantage in the rally away from Thiem.

Kyrgios has another animated chat with the umpire. He has already been docked a point and he hit a ball out the ground and is on the thinnest of ice.

Thiem meanwhile still looks the calmest man out there. He holds to 15 in the next, a lovely shot at the feet of Kyrgios can't be recovered. Neither man has had their serve threatened in this set.

And the Aussie fans are waving their flags again. It comes after Kyrgios still has the energy to sprint to the net to punch away a volley. Game Kyrgios.

Image source, Getty Images

Another hold to love from Thiem. Who has the greater energy? Who is going to triumph? Another heated chat with the umpire from Kyrgios. The match is approaching three hours and we're tied at 2-2 in games and 2-2 in sets.

Alan Peevers: Why do people slam Kyrgios for underarm serving? It’s a legitimate tactic whatever the level of tennis and especially useful against players who receive serve very deep. It keeps them honest.

Time check: 10:15 pm in Melbourne. Everyone has to be home by midnight. No-one wants to leave yet though.