Finch scored a 45-ball 55 to anchor Australia’s chased a 163-run target after Ellis took 4-28 kept Pakistan down to 162-8 in their allotted 20 overs.
Pakistan failed to reach a big score despite skipper Babar Azam’s brisk 46-ball 66 with six fours and two sixes.
Watch Australia’s Tour of Pakistan on Kayo. Every ODI and T20 Live & On-Demand. New to Kayo? Try 14-Days Free Now >
A cheeky Finch joked post-game: “I’m glad we don’t have to bowl to Babar anymore for a while”.
Finch, who had not scored a half century in the last 13 T20Is, ensured he not only removed doubts over his batting but also helped Australia overhaul the target in 19.1 overs for the loss of seven wickets.
When Finch holed out Australia needed just four runs and despite Sean Abbott fell for nought in the same Shaheen Shah Afridi over, Ben McDermott hit the winning boundary in his 19-ball 22 not out to achieve Australia’s fourth successive win in T20Is against Pakistan.
Finch, who hit six boundaries, put on a brisk 40 for the opening stand with Travis Head (14-ball 26 with three fours and a six) and another 44 for the second with Josh Inglis who made 15-ball 24 with two fours and a six.
Pakistan did pull back with leg-spinner Usman Qadir (2-33) and pacer Mohammad Wasim (2-30) brought the home team back in the game.
But Marcus Stoinis (nine-ball 23 with five boundaries) and McDermott ensured they supplement their skipper to achieve the chase.
“I thought the way our bowlers attacked that game were fantastic,” said Finch.
“Nathan Ellis had a tough start but showed real character and we took wickets upfront.” Pakistan skipper Azam rued loss of wickets after a good start.
“We had a very good start but then lost couple of wickets that took away the momentum,” said Azam.
“We lost momentum and in the end were 20-30 runs short.”
Pakistan lost momentum after a brisk start.
Azam, who hit back to back hundreds in Pakistan’s 2-1 win in the one-day international series, put on 67 for the opening wicket with Mohammad Rizwan (23) after Australia sent the home team in to bat at Gaddafi Stadium.
But Green dismissed Rizwan with the fourth ball of his first over and Fakhar Zaman off a full toss next ball to pull things for Australia.
Azam drove Green for a four to bring up his 26th T20I fifty off just 33 balls. He smashed spinner Adam Zampa for a six but next ball holed out at deep cover.
Khushdil Shah chipped in with 21-ball 24 and Usman Qadir six-ball 18 not out as Pakistan managed 50 runs in the last five overs, losing five wickets.
Marnus Labuschagne, Ben Dwarshuis and Green were handed Twenty20 international debuts by Australia.
Scoreboard of the Twenty20 international between Pakistan and Australia in Lahore:
Mohammad Rizwan b Green 23
Babar Azam c Ellis b Zampa 66
Fakhar Zaman c Finch b Green 0
Iftikhar Ahmed c Inglis b Ellis 13
Khushdil Shah c McDermott b Ellis 24
Asif Ali c Labuschagne b Ellis 3
Hasan Ali b Abbott 10
Shaheen Shah Afridi c Stoinis b Ellis 0
Mohammad Wasim not out 2
Usman Qadir not out 18
Extras: (lb2, nb1) 3 Total: (for eight wkts; 20 overs) 162 Did not bat: Haris Rauf
Fall of wickets: 1-67 (Rizwan), 2-67 (Zaman), 3-93 (Iftikhar), 4-118 (Azam), 5-127 (Asif), 6-142 (Hasan), 7-142 (Khushdil), 8-142 (Shaheen)
Bowling: Head 2-0-17-0, Dwarshuis 3-0-42-0, Abbott 4-0-28-1 (nb1), Ellis 4-0-28-4, Zampa 4-0-29-1, Green 3-0-16-2
T. Head c Qadir b Rauf 26
A. Finch c Asif b Shaheen 55
J. Inglis c Rizwan b Qadir 24
M. Labuschagne st Rizwan b Qadir 2
M. Stoinis b Wasim 23
C. Green b Wasim 2
B. McDermott not out 22
S. Abbott b Shaheen 0
B. Dwarshuis not out 0
Extras: (lb5, nb1, w3) 9 Total: (for seven wkts; 19.1 overs) 163 Did not bat: Nathan Ellis, Adam Zampa
Fall of wickets: 1-40 (Head), 2-84 (Inglis), 3-95 (Labuschagne), 4-119 (Stoinis), 5-129 (Green), 6-158 (Finch), 7-159 (Abbott)
Bowling: Shaheen 4-0-21-2 (w1), Hasan 3-0-30-0, Rauf 3.1-0-35-1, Qadir 4-0-33-2 (nb1, w1), Khushdil 1-0-9-0, Wasim 4-0-30-2 (w1)
Result: Australia won by three wickets