Despite edging ahead, Murray is not a happy bunny after that wrong double bounce call. He marches back to his seat, wagging and pointing his finger towards the umpire Jake Garner. There are also a few words - likely to be unrepeatable - exchanged.

Image source, Getty Images

Murray manages a broad smile at the end of that previous game as he prepares to serve. I wouldn't be smiling if I'd just blown those chances.

But that soon turns into a scowl as the Briton claims a frankly unbelievable return from Dimitrov bounced twice. And he's right! However, Murray still manages to win that point for 40-15 and closes out for the hold.

Murray decides to stand up again to the Dimitrov serve, meeting every one with a firm forehand at the baseline. That earns him a break point early in the third, only to plant this chance at 40-30 into the net.

The Bulgarian offers another invitation at deuce, which is again declined, then offers a third with a double fault. Murray does not take advantage and passes up a fourth break too after the sole-squeaking pair scamper around court.

Dimitrov finally sees daylight in this tunnel of an eight-minute game and makes Murray pay at the first chance.

Laura Lambert:, external Level in scores at 1-1, but mentally Dimitrov leads having twice come back from a break down in 2nd set. Are we on for an epic? #bbctennis

Matty Hernandez:, external Baby Fed is smashing it against Muzza #bbctennis

After the high-energy, high-tempo opening two sets, this third set is proving to be a far more sedate affair. The server, this time Murray, controls the game again as Dimitrov can't find his returning game.

"Whatever you can do I can do better," is what Grigor Dimitrov may or may not be singing in his head. The Bulgarian follows Murray's lead, holding his service game to love too.

But Murray's rage clearly worked as a cathartic release. The next game? A quickfire hold to love.

Murray is absolutely livid with himself. The Briton throws his racquet to the ground, threatens to fling his water bottle into the Melbourne air like a frisbee, then shouts and gesticulates like a madman. Get that anger out Andy...

Image source, AP

Murray misses a sitter of a backhand, instead going for the lob which Dimitrov snaffles without a second thought. That's 3-2 to Dimitrov. Not for long....

What. A. Pass! The Rod Laver Arena is up on its feet as Dimitrov sprints, scampers and stretches to answer a host of Murray questions which are being peppered all over the court. Then, somehow beats the Briton with a wonderful passing winner.

He breaks again for 5-2, before Murray nicks one back. Not for long though as the Briton smashes a forehand return into the net. Three set points...

One saved. Two saved. But not the third. Dimitrov's booming serve is meekly returned into the net by Murray and the Bulgarian goes nuts.

And that error from the British number one means it is time. Tie-break time!

Dimitrov has never fought back from two-sets down to win - and he still doesn't have to. Yet.

A couple of strange shots from Murray sees him trail 30-0, then Dimitrov reads his serve again for two break points. Lifeline for the Bulgarian.

He doesn't accept either offer though, sliding two cross-court forehands wide. Murray earns a reprieve but Dimitrov, seemingly with the backing of the Aussie crowd, goes on the offensive. He volleys a winner for the advantage and Murray, inexplicably, double faults for the game. A gift.

Is this the second-set break that Murray craves? Yes it is!

The British number one has three bites of the break apple, but sinks his teeth into the first as he forces Dimitrov into a wayward lob which drifts out of the court.

Now he is serving for the second set...

This is top drawer tennis. Murray edges a 17-shot rally to go 30-15 ahead, drawing more support from a couple of young ladies covered in face paint and draped in Saltires.

Then, the Scot sees out the game with a couple of strong serves. Solid stuff. Now where's that break gone...

Murray cranks up the pressure again. Dimitrov lurches forward and bundles into the net to trail 30-0. The Briton sees his lob picked off before he earns two break points with a pair of brutal backhands.

One goes begging with an awkward backhand that pings out to Dimitrov's left. The other? That also goes begging with an awkward forehand that pings out to Dimitrov's right.

Deuce it is. Murray's missus Kim Sears offers an encouraging clap for her man, who survives a couple of game points. But he doesn't survive a third as his drop shot floats into the braided mesh. Chance(s) gone.

Gigi Salmon
BBC Radio 5 live sports extra commentator

"Dimitrov gives a fist pump but he is having to work so hard for everything."

Ben Roach:, external WHAT A WIN FOR KYRGIOS! 5 set thriller! Murray has a good record against him. Just Dimitrov to dispose of first... #AusOpen #bbctennis

Shohidur Rahman:, external Krygios you beast. What a comeback! #bbctennis

Ian Rhodes:, external Great to see some of the younger payers really stepping their game up @AustralianOpen #bbctennis

Move on, nothing much to see here. Routine service game for Murray, as he holds to love.

Piers Newbery
BBC Sport at Melbourne Park

"A real goosebumps moment as the crowd on Laver erupts at the news that Kyrgios has won that epic on Hisense. Prolonged applause delays Murray and Dimitrov at the not insignificant point of 3-3, deuce. Another burst of applause follows as the Kyrgios news flashes up on the scoreboard at the changeover. It has been 39 years since an Australian man won the title."

If this was an arm wrestle then Dimitrov would be back in an upright position. Murray was pushing down hard at a set and a break up, threatening to apply the pressure.

But the Bulgarian has found some much-needed energy and resolve - not least in this game. The 23-year-old is under the cosh again as the pair exchange several points at deuce, before desperately clinging on to his serve.

Image source, AFP

Fans stand and applaud inside the Rod Laver Arena as news filters through from the other court that home favourite Nick Kyrgios has won his five-set duel with Italian Andreas Seppi.

He came from match point down to defeat Roger Federer's conqueror 5-7 4-6 6-3 7-6 (7-5) 8-6.

The 19-year-old says he has no preference between Murray and Dimitrov for his quarter-final opponent.