Australia's surging one-day international form has continued after Aaron Finchís monster century and a dominant partnership with Usman Khawaja propelled them to another comprehensive win over Pakistan in Sharjah.

Finch (153 not out off 143) amassed his second century in as many games, while Khawaja (88 off 107) picked up where he left off in the recent series against India in posting another substantial total from the top of the order.

It was an extraordinary innings from Finch, who smashed six sixes in arguably the finest knock of his career. It was his 13th ODI century, with only David Warner (14 ODI tons) ahead of him among active Australian players.

The eight-wicket win was eerily similar to Friday's at the same ground when they reeled in 281, with the opening two matches of the series marking two of the three highest run chases at the venue that has hosted more ODIs than any other.

There were a few nervy moments in the dying overs, but the result never truly appeared in doubt as the tourists claimed the same margin of victory as two days earlier, dropping just two wickets en route to their target.

Itís the first time since 2016 Australia have won five consecutive ODIs.

Pakistan's decision to promote Mohammad Rizwan up from No.8 to No.4 had earlier proved canny, with the wicketkeeper-batsman cracking his maiden ODI century to see Pakistan post a competitive 7-284.

But an exhilarating entrance to international cricket from debutant tearaway Mohammad Hasnain aside, Pakistan barely fired a shot with the ball as Finch and Khawaja both played chanceless innings.

Their 209-run stand was Australia's fifth-highest ODI opening partnership.

The only negative for the tourists was an injury to Jhye Richardson, whose involvement in the remainder of the five-game series is in question after the paceman dislocated his shoulder in a nasty fall.

Rizwan shared in a 127-run fifth-wicket partnership with skipper Shoaib Malik after his side had wobbled to 2-35 and then 4-112 nearing the halfway point of their innings.

Rizwan is standing in behind the stumps for regular captain and gloveman Sarfraz Ahmed, but his well-crafted 115 off 126 balls will have done his hopes of making Pakistan's World Cup squad no harm.

After Malik won the toss and batted for the second time in three days, Richardson's afternoon began far better than it ended less than an hour later, offering another glimpse of his skills with the new ball.

Australia's pacemen had failed to make any early inroads on a similar-looking pitch from the first game, but two days later, Richardson had both openers dismissed inside the first six overs.

But the Western Australian was also soon back in the sheds, sporting a blue brace around his right arm to signal the end of his involvement in the game, and possibly the series.

What began as a likely tactic to make up Richardson's remaining overs turned out to be a masterstroke from Finch, who brought himself on to send down his part-time left-arm spinners and duly had first ODI century-maker Haris Sohail caught behind for 34.

Finch went on to concede just 41 from his 10 overs, the most frugal full set of the innings, not to mention the first time he'd bowled more than four overs in an ODI.

Big-hitter Umar Akmal inexplicably holed out off Nathan Lyon to leave Pakistan at a crossroads, but the Rizwan-Malik duo smartly charted a course through the middle overs that kept the run-rate ticking along at close to six-an-over.

Rizwan's delight at reaching triple figures, off 114 balls, was palpable, flashing a beaming smile and cheeky salute back to his teammates.

Maxwell was a magnet to the ball in the final overs, making up for a rare drop running in from long-on by making no mistake when Malik offered the same opportunity two overs later.

The dynamic allrounder then pulled off a piece of boundary-line magic to end Rizwan's innings, serenely pouching a high ball, expertly shifting his right foot sideways to avoid contact with the boundary triangle, throwing the ball back up in the air and taking the rebound after righting himself.

From ball one of their reply, nothing troubled Australia's opening pair of Finch and Khawaja, who sent the score racing past 50 after 11 overs, past 100 after 19, 150 after 25 and 200 after 34.

The introduction of Hasnain, who Pakistan legend Waqar Younis said should have opened the bowling, gave Finch and Khawaja plenty to think about with a series of vicious short balls.

But after a hostile opening spell that saw Finch struck on the helmet, the 18-year-old, who had never played a domestic one-dayer let alone a fully-fledged ODI before Sunday, posed less of a threat as the night wore on and the opening stand grew ever larger.

Pakistan briefly had their tails up after Khawaja was finally out slog sleeping and the promoted Maxwell, after twice smashing Imad Wasim onto the stadium's roof, ran himself out.

A run-a-ball chase for the final six overs suddenly looked a tricky one, as Pakistan missed a series of run-out opportunities and scoring became tougher on a wearing track with a ball beginning to reverse-swing.

But after bringing up his first-ever ODI 150, Finch hit the winning runs to give the Aussies a 2-0 series lead.