Pakistan grabbed three key wickets to restrict New Zealand to 151-4 at tea Thursday, as both teams wrestle for a series-clinching win in the second Test in Karachi.

At the break on day four, Tom Blundell and Michael Bracewell were at the crease with 22 and 10 respectively, as the visitors extended their lead to 192 with six wickets intact.

Despite the National Stadium pitch still not causing trouble for the batters, Pakistan pegged back the visitors from 76-1 at lunch with the wickets of Tom Latham (62), Kane Williamson (41) and Henry Nicholls (five).

Latham was smartly caught off a miscued flick at short mid-wicket by Abrar Ahmed from fast-bowler Naseem Shah.

With the total unmoved on 114, in the next over Ahmed trapped Williamson leg-before. Hasan Ali had Nicholls caught soon after as New Zealand lost three wickets off 50 balls for 14 runs.

Field umpires Alex Wharf and Aleem Dar had a horrible day with three of their decisions overturned.

New Zealand were jolted in the second over of their innings when Mir Hamza bowled Conway with his first delivery.

It was the first time Conway fell without scoring in his 12-match Test career.

Pakistan wasted two leg-before referrals on Williamson when the batter was on seven and nine, while Latham overturned a decision against him on 36 -- all off Ahmed.

At the start of the day, Pakistan were dismissed for 408 after adding just one run to their overnight score, in response to New Zealand's 449 first-innings total.

Spinner Ish Sodhi had last man Ahmed trapped leg-before for nought, leaving centurion Saud Shakeel stranded on the other end.

Shakeel was unbeaten on 125 after a marathon resistance-packed 493 minutes at the crease, hitting 17 boundaries in his maiden hundred.

Spinner Ajaz Patel finished with 3-88 and Sodhi 3-95.

The two-match series is tied after the first Test -- also in Karachi -- ended in a draw.

Scoreboard

New Zealand 1st innings 449 (D. Conway 122, T. Latham 71, M. Henry 68 not out; Abrar Ahmed 4-149)

Pakistan 1st innings (overnight 407-9)

Abdullah Shafique c Patel b Henry      19

Imam-ul-Haq c Blundell b Southee       83

Shan Masood c Conway b Patel           20

Babar Azam run out                     24

Saud Shakeel not out                  125

Sarfaraz Ahmed st Blundell b Mitchell  78

Agha Salman c Bracewell b Patel        41

Hasan Ali c Conway b Patel              4

Naseem Shah b Sodhi                     4

Mir Hamza b Sodhi                       0

Abrar Ahmed lbw b Sodhi                 0

Extras (lb7, nb3)                      10

Total (all out, 133 overs)            408

Fall of wickets: 1-27 (Shafique), 2-56 (Masood), 3-99 (Azam), 4-182 (Haq), 5-332 (Sarfaraz), 6-385 (Salman), 7-393 (Hasan), 8-397 (Naseem), 9-397 (Hamza)

Bowling: Southee 25-7-62-1, Henry 28-9-58-1 (1nb), Patel 17-2-88-3, Bracewell 26-3-87-0, Sodhi 27-3-95-3 (2nb), Mitchell 10-6-11-1

Toss: New Zealand

Umpires: Alex Wharf (ENG) and Aleem Dar (PAK)

TV umpire: Ahsan Raza (PAK)

Match referee: David Boon (AUS)