Afridi’s 50-ball 71 supplemented by Kamran Akmal’s undefeated 43-ball 67 and Khalid Latif’s steady maiden fifty lifted Pakistan to an imposing 287-9 before they shot New Zealand out for 149 in the 40th over.
The victory, which gave Pakistan a 1-0 lead in the three-match one-day series, was also a sweet revenge for the winners who lost to New Zealand in the Champions Trophy semi-final last month.
The remaining two matches will be played here on Friday and Monday, before the two teams move to Dubai for two Twenty20 internationals on November 12 and 13.
Chasing a daunting target, New Zealand were never on course as Gul shook them by bowling Brendon McCullum (21) and Martin Guptill (four) by the tenth over.
Teenager Mohammad Aamir accounted for Ross Taylor (nought) and Abdul Razzaq sent Scot Styris (five) back as New Zealand reeled at 50-4.
Aaron Redmond (52) and Daniel Vettori (38) provided the only resistance during a 69-run fifth wicket stand before five wickets fell for 10 runs.
Earlier, it was Akmal who gave Pakistan’s innings the final touches with a belligerent 43-ball 67 laced with four sixes and five boundaries as Pakistan ran rampant, making 107 in the last ten overs.
He built on vice-captain Afridi’s innings, who was instrumental in initially stepping up the run-rate with his bold hitting as he smashed three sixes and four boundaries during his 30th half-century.
Afridi added 101 runs for the fifth wicket with Latif after New Zealand paceman Shane Bond dismissed opener Salman Butt and Younus - both without scoring - in his incisive five-over spell.
Latif, who scored 19 in his only previous one-day match in January last year, was also involved in a 57-run stand for the third wicket with Mohammad Yousuf, who shaped well for his 30 before being run out.
Afridi hit Vettori for a six before smashing two off successive deliveries off Nathan McCullum. He hit Bond for a straight drive to reach his half-century off 36 deliveries, his first in 33 matches.
Afridi’s last ODI fifty came against Zimbabwe at Multan last year.
Latif hit only two boundaries during his 112-ball knock.
Kamran’s innings was special as he made full use of the power-play, and added 86 off just 37 balls for the seventh wicket with Abdul Razzaq, who made 20-ball 26.
The limited over series was relocated to Abu Dhabi after New Zealand refused to tour Pakistan over security fears.
Pakistan:
Salman Butt c B. McCullum b Bond 0
Khalid Latif b Vettori 64
Younus Khan c B. McCullum b Bond 0
Mohammad Yousuf run out 30
Umer Akmal b Vettori 9
Shahid Afridi c Butler b Oram 70
Kamran Akmal not out 67
Abdul Razzaq c Styris b Butler 26
Umar Gul run out 0
Mohammad Aamir c B. McCullum b Southee 0
Saeed Ajmal not out 0
Extras: (lb8, nb2, w11) 21
Total: for nine wkts 287
Fall of wickets: 1-0 (Butt), 2-0 (Younus), 3-57 (Yousuf), 4-57 (Umer), 5-176 (Afridi), 6-184 (Latif), 7-270 (Razzaq), 8-271 (Gul), 9-277 (Aamir)
Bowling: Bond 10-2-61-2 (8w), Southee 10-2-54-1, Butler 7-0-54-1 (2nb, 2w), Oram 10-0-47-1 (1w), Vettori 10-1-34-2, N. McCullum 3-0-29-0
New Zealand:
B. McCullum b Gul 21
A. Redmond lbw b Ajmal 52
M. Guptill b Gul 4
R. Taylor c Kamran b Aamir 0
S. Styris c sub (Farhat) b Razzaq 5
D. Vettori b Afridi 38
J. Oram b Razzaq 9
N. McCullum lbw b Afridi 0
I. Butler run out 4
S. Bond not out 4
T. Southee lbw b Ajmal 1
Extras: (lb8, nb1, w2) 11
Total: 149
Fall of wickets: 1-30 (B. McCullum), 2-34 (Guptill), 3-35 (Taylor), 4-50 (Styris), 5-119 (Redmond), 6-139 (Vettori), 7-139 (N. McCullum), 8-139 (Oram), 9-144 (Butler)
Bowling: Aamir 7-1-15-1, Gul 6-3-24-2 (1nb), Razzaq 9-1-38-2, Afridi 10-0-46-2 (2w), Ajmal 7.2-0-18-2
Overs: 39.2
Result: Pakistan won by 138 runs
Toss: Pakistan
Umpires: Bruce Oxenford (AUS), Asad Rauf (PAK)
Tv Umpire: Zameer Haider (PAK)
Match Referee: Andy Pycroft (ZIM)