Set an imposing 354 to win, Pakistan were never really in the hunt.
After Australia made 353 for six on the back of a David Warner century that was aided by appalling fielding from the tourists, Pakistan replied with 267 from 43.5 overs.
A frustrated Arthur was left lamenting another sloppy fielding effort marked by a number of dropped catches.
"We can't compete with a side like Australia if we give their top five that many chances," he said. "It's unacceptable, those standards we set as a cricket team those standards haven't been met. Is it skill level, attitude, or is it fatigue?"
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Warner backed his form with the bat by doing what the Pakistanis couldn't and hanging on to two excellent catches.
He was pleased to have the series wrapped up ahead of the final game in Adelaide on Thursday, saying the team "played fantastic".
After Australian captain Steve Smith won the toss, the home side took advantage of a placid wicket and the hapless Pakistan fielding.
Warner top-scored with 130 but Pakistan did not help themselves, conceding a number of overthrows and dropped catches at crucial times. He was dropped on 113 when Hasan Ali grassed a simple chance at mid-off from spinner Imad Wasim.
Sharjeel also dropped Travis Head when he was on 28, again to the chagrin of the luckless Junaid. Head went on to make 51. And Hasan put down a difficult chance off Glenn Maxwell when he was on eight and the Australian ended on 78.
Despite his two dropped catches Hasan redeemed himself by taking five for 52, easily the best of the Pakistan bowlers.
Warner and Smith put on 120 for the second wicket to put Australia in a commanding position before Hasan removed both in the space of three balls to give the tourists a lift.
Zampa, controversially overlooked for the upcoming India tour, took his opportunity with 3-55 from his 10 overs.