Published: 2019-03-25 01:43:57 BdST
Finch, who hit 116 in the first game, followed it up with a career-best unbeaten 153, including 11 boundaries and six sixes, while Khawaja missed out on what would have been his third century of the month, scoring a patient 88 off 109 as Australia took a 2-0 lead in the series.
The pair put on 209, a record opening stand for Australia while chasing in ODIs which bettered Mark Waugh's and Adam Gilchrist's partnership of 206 against West Indies in 2001.
Both Finch and Khawaja have notched up high scores this month and their form will give Australia a selection headache for the upcoming World Cup after David Warner, nearing the end of his international ban, hit 85 off 53 on his return to the Indian Premier League earlier on Sunday.
Pakistan had won the toss and skipper Shoaib Malik elected to bat first, setting Australia a target of 285 to win, anchored by Mohamed Rizwan's maiden ODI century.
Richardson completed only half his quota of overs, however, after he was forced off the field when he dislocated his shoulder while trying to save a boundary. The 22-year-old did not return and was later seen with his arm in a sling.
Finch stepped up to bowl in Richardson's place and he picked up only his third ODI wicket when he had Haris Sohail caught behind for 34. Umar Akmal (16) also departed cheaply when he holed out to Peter Handscomb in the deep trying to attack Nathan Lyon.
Rizwan, who was promoted up the order, steadied the innings with Malik, who scored 60, as they notched up a 127-run partnership for the fourth wicket until Adam Zampa got Malik caught at long on.
Rizwan departed for 115 in the 47th over when he tried to accelerate the innings, caught at the long-on boundary off Nathan Coulter-Nile by a back-tracking Glenn Maxwell, who had to throw the ball back in to avoid stepping outside the rope.
The win was Australia's fifth in a row after their 3-2 comeback in the series in India earlier this month. The third match of the five-match series will be played on Wednesday in Abu Dhabi.