There is a degree of inevitability about Australia in Test cricket.

Pakistan has played exceptionally in Melbourne, taking the fight to Australia at every opportunity with bat and ball.

But no matter how tough things got, Australia always had an answer.

"It's just what happens. Pat Cummins and Australia, they just know," former England captain Michael Vaughan said.

In truth, not many people expected it to matter against Pakistan, a team that had unfairly been dismissed as cannon fodder ahead of this summer of cricket.

But that Australian mentality mattered in this Test match.

Look at what happened on day three, when the hosts were stunningly reduced to 4-16.

Australia needed a partnership, so Steve Smith and Mitch Marsh delivered one.

No matter that 4-16 was the lowest base score from which a fifth-wicket partnership has delivered a century in Test cricket history.

No matter that Mir Hamza was having the best Test of his short career, swinging the ball in and out and asking questions with every delivery, aided and abetted by Shaheen Shah Afridi, Hassan Ali and Aamir Jamal.

Australia simply found a way, found the composure to ride out the storm and rethink its options in order to move forward.

There was luck. Wasn't there a whole lot of luck?

The frankly shocking drop of Marsh on 20 by Abdullah Shafique cost Pakistan a whopping 76 runs and all the initiative it had built up.

But the point is that Australia, somehow, got through it.

The same thing happened on day four with the ball.

"They just know how to get that key wicket at the key moment. They have that switch," Vaughan said.

Shan Masood was more blunt.

"They're ruthless," he said.

After the early wickets of the unfortunate Shafique and Imam-ul-Haq, Masood himself took on the challenge and was driving Pakistan forward with a 61-run partnership with Babar Azam.

But Cummins was never going to let Pakistan get too far away.

If Cummins was unlikeable you could confer on him the title of Thanos, a comic book god with a desire to obliterate everything in his path.

Much like Thanos in the Marvel films, he is inevitable, possessing the ability to click his fingers and evaporate half the opposition batting line-up with a disarming smile and lightning swing of his pacy right arm.

That's what he did on day four at the MCG, his second five-fa in the match to record just his second 10-wicket haul in a single Test.

Masood was looking immensely confident in passing 50 at almost a run a ball.

Cummins brought himself on and, just like that, the Pakistan skipper was on his way, caught brilliantly by Smith.

It was akin to his field change to effect dismissals earlier in the Test. And other times he has come on to change the tenor of a Test with his ability.