Yasir led the varied attack with 3-54 as New Zealand, who won the toss and batted on a grass-less Sheikh Zayed Stadium pitch, were bowled out for a below-par 153 in 66.3 overs at the stroke of tea.
The day saw 12 wickets fall as Pakistan closed at 59-2, having lost both their openers Imam-ul-Haq (six) and Mohammad Hafeez (20) before Haris Sohail (22 not out) and Azhar Ali (10 not out) stopped the rot.
Pakistan need 94 more to take a lead and enforce a 1-0 lead in the three-match series.
Imam was first to go as he edged Colin de Grandhomme's delivery to the slip while Hafeez miscued a pull straight to short mid-wicket -- both caught by Kane Williamson.
New Zealand skipper Williamson, declared fit after missing last Sunday's third one-day international due to a groin injury, top-scored with 63 before falling softly to medium pacer Hasan Ali, who finished with 2-38.
Hasan removed Williamson with a slower delivery as the New Zealand skipper went for a hook and gloved the ball for wicketkeeper Sarfraz Ahmed's fourth catch of the innings.
Williamson's 112-ball knock had five boundaries and he added 72 for the fourth wicket with Henry Nicholls who made 28 with four boundaries.
In the same over Hasan trapped De Grandhomme for a first-ball duck before Sohail dismissed Ish Sodhi (four) and BJ Watling (four) -- both were trapped leg-before.
Mohammad Abbas, who has figures of 2-13, had removed Nicholls, caught behind by Sarfraz soon after lunch.
Pakistan dominated the first session as New Zealand were 81-3 at lunch, with leg-spinner Yasir Shah taking the first of his two wickets in his opening overs.
Yasir had derailed New Zealand's progress in the first session with the wickets of opener Tom Latham (13) and Ross Taylor (two) in his first spell.
New Zealand openers Jeet Raval and Latham survived some anxious moments before pace spearhead Mohammad Abbas had Raval edging to wicketkeeper Sarfraz Ahmed after scoring seven.
Yasir, who had to endure a tough last week due to the death of his mother, had Latham caught at mid-wicket off a loose drive with the fourth ball of his first over.
In his fourth over Yasir had Taylor caught behind with a sharp leg-break, leaving New Zealand at 39-3.
New Zealand handed Test debut to 30-year-old left-arm spinner Ajaz Patel, leaving out experienced pacer Tim Southee.
The second Test is in Dubai (November 24-28) and third in Abu Dhabi (December 3-7).
First Published: November 16, 2018, 7:44 PM IST