On Friday Duckett had said debutant Abrar Ahmed - who took seven wickets in the first innings - was just a leg spinner with a googly, but the Nottinghamshire batter became the 24-year-old's 10th scalp of the match in the evening session on day two.
Duckett went to pull a ball which stayed low and was bowled for 79 by Abrar, who became the 18th player in men's Test cricket to take 10 wickets in their first match.
Duckett had already had a stroke of fortune on 69 when he parried a long hop straight to midwicket at a very catchable height, but he was put down by Pakistan captain Babar Azam.
Brook brought up a half-century of his own and finished the day on 74 not out having looked confident and comfortable at the crease, with Ben Stokes also unbeaten on 16 having come in at number seven.
Ollie Pope, who came in at number six after being given a longer break following his spell as wicketkeeper, was run out for four attempting a suicidal run and was unable to get back into his ground.
Despite their attacking brand of cricket since Stokes took over as captain, there was a markedly more measured approach in the second innings, with the game already into the third innings on only the second day.
England lost their first wicket early, with Zak Crawley run out when taking a risky and unnecessary single with the tourists 11 for one.
The opener was run out by Abrar, who continued his memorable debut at Multan, but fortunately for the tourists it did not spark a significant collapse.
Will Jacks came in at number three and became Abrar's eighth wicket of the match when he was bowled swiping across the line for just four.
Joe Root fell to Abrar for a second time in the match, for 21 in the final wicket before tea.
The Yorkshireman had been looking relatively comfortable against the mystery spinner, but was caught by a stunning one-handed diving catch from Abdullah Shafique at short leg.
The on-field umpire reviewed the catch, but replays showed the fielder had expertly just managed to get his hands underneath the ball, despite his momentum going the other way.
In the morning session, England made crucial inroads as Pakistan collapsed from 107 for two overnight to being bowled out for 202 at lunch.
The wickets fell rapidly throughout the morning session, with Jack Leach capitalising on a turning pitch to finish with four wickets for 98 runs as the hosts lost eight wickets for just 60 runs.
Saud Shakeel had just brought up his half-century but finished with an attritional 63 from 106 deliveries and became Leach's 100th Test scalp - with the spinner becoming the 49th English cricketer to reach the milestone.
As part of the hosts' collapse, England took three wickets for no runs as part of a spell of five wickets for 11, before Mark Wood wrapped up the tail to allow England the luxury of being able to take their time to score runs and try and take wickets across multiple sessions.