Sohail scored a 129-ball 130 for his second one-day international hundred but failed to take Pakistan past Australia's imposing 327-7, finishing at 307-7 in 50 overs.
Australia's total was built around Usman Khawaja's 98 and a fiery 33-ball 70 by Glenn Maxwell coupled with Shaun Marsh's 61 and skipper Aaron Finch's 53 in a dominating batting show.
The series win gives Australia an eighth straight ODI victory following their 3-2 series win in India after losing the first two matches.
It gives them a sixth successive series win over Pakistan since losing in 2002 (in Australia) and fourth whitewash over their opponents -- 1998 (3-0 in Pakistan), 2010 (5-0 in Australia) and in 2014 (3-0 in United Arab Emirates).
Australia's resurgence -- after winning just three of their 18 matches between January 2018 to the first two matches in India earlier this month -- could not have been more perfectly timed as they defend their World Cup title in England in two months.
Sohail, who hit 11 boundaries and three sixes, had set up the chase during a second-wicket stand of 108 with Shan Masood (50 off 54 balls) and another 102 with Umar Akmal (44-ball 43) before Australia hit back with two wickets in the space of one run.
Umar holed out to off-spinner Nathan Lyon and a run later Sohail's innings was ended by Kane Richardson.
Stand-in skipper, Imad Wasim deputising for injured Shoaib Malik (captain for the series), hit a 34-ball 50 not out with six boundaries and a six but it proved futile.
Pakistan had lost Abid Ali -- who made a debut hundred in the last game -- for nought in the first over.
Earlier, Khawaja and Maxwell made merry against Pakistan's bowling attack.
It was Maxwell's ten fours and three sixes that helped Australia to 107 runs in the last ten overs. He was finally bowled by paceman Junaid Khan who finished with three wickets for 63.
Khawaja, who hit ten boundaries in his 111-ball innings, set the platform with a solid 134-run opening stand with Finch for the pair's second hundred run stand in the series.
Finch was finally bowled by pacer Usman Shinwari, finishing with 451 runs in the series, only 27 short of George Bailey's record in a bilateral series he made against India in 2013.
Khawaja, who made his first two ODI career hundreds in India earlier this month, was all set for his third but fell to a miscued drive off Shinwari, who finished with 4-49.
Khawaja added 80 for the second wicket with Marsh who hit five fours and a six in his 68-ball knock.
Australia won the first two matches in Sharjah by identical margins of eight wickets before winning the third in Abu Dhabi by 80 runs and fourth in Dubai by six runs.
First Published: April 1, 2019, 1:26 AM IST