A rampant Australia beat Pakistan by an innings and 18 runs in the second Test at the Melbourne Cricket Ground to clinch the three-Test series 2-0 on Friday.

The Australians roared to victory in the last two sessions of the final day dismissing the tourists after declaring before lunch at 624 for eight.

Pakistan went into the final session at 91/5 and managed to rack up 163 before the middle-order collapsed with three crucial wickets taken by Aussie bowler Nathan Lyon.

Lyon, whose bowling consistency has been questioned by captain Steve Smith, produced an inspired two wickets in three balls to put Pakistan on the slide and Australia on track for a stunning final day victory.

He coaxed Younis Khan to push forward and be caught by Peter Handscomb centimetres off the ground at short leg for 24 and then dismissed skipper Misbah-ul-Haq to an injudicious sweep for a duck.

Misbah swept outside his off-stump to Nic Maddinson placed at short fine leg for the premeditated shot.

Suddenly both of Pakistan's two experienced batsmen were gone and four wickets down with Australia attacking with their tails up.

Mitchell Starc capped off a big-hitting 84 off 91 balls to take four wickets to help dismiss Pakistan and propel Australia to a final day victory.

Pakistan went into the final session with first innings double-centurion Azhar Ali on 34 and Sarfraz Ahmed on one and still trailing by 90 runs.

Skipper Steve Smith was left unbeaten on 165 when he called a halt to the massive Australian first innings to give his bowlers a minimum of 70 overs to see off the tourists.

But the Australians only needed 53.2 overs to bowl out Pakistan with Starc taking four for 36 and off-spinner Nathan Lyon capturing three for 33.

Australia won the series ahead of Tuesday's final Test in Sydney with Pakistan now having lost their last 11 Tests in Australia.