Pakistan lost opener Abdullah Shafique and Shan Masood Tuesday after a chaotic start to their innings before reaching 62-2 at tea on the second day of the second Test against New Zealand in Karachi.
At the break, Imam-ul-Haq and Babar Azam were at the crease on 17 and four respectively after New Zealand's tail-enders lifted their team to a handy 449 runs.
Pakistan now trail by 387 with eight wickets intact on a slow National Stadium pitch.
The two-match series is tied after the first Test, also in Karachi, ended in a draw.
Shafique was the first Pakistan wicket to fall when he pulled pacer Matt Henry's short delivery straight to the hands of Ajaz Patel for 19.
Shan Masood continued his miserable form, cutting spinner Patel to point fielder Devon Conway on 20.
Henry and Patel had combined earlier to lift New Zealand from 345-9 with an invaluable 104 runs for the 10th wicket.
Henry smashed eight boundaries and two sixes in his career-best 68 not out, improving his previous high against Australia at Christchurch in 2016 by six runs.
Patel also bettered his previous Test-best of 20 -- against England last year -- by scoring 35 before he was the last wicket to fall, caught off spinner Abrar Ahmed.
Naseem took the day's first wicket when he bowled Ish Sodhi for 11 with a ball that cut through sharply.
Blundell, who was 30 overnight, reached his fifty with a boundary and a single off Abrar Ahmed. He hit six boundaries in his 51 before being bowled by Ahmed.
The spinner then had Tim Southee stumped for ten, before Henry and Patel prolonged the innings, helping New Zealand cross the 400-mark.
Ahmed was the pick of the bowlers with 4-149 while Naseem Shah (3-71) and Agha Salman (3-75) were the other successful bowlers.