The tourists, already facing the possible loss of their captain Michael Vaughan due to a knee injury, failed to defend a 245-run target against Pakistan 'A' on the third and final day.
England, who will know the fate of Vaughan later Tuesday, now have just three days to overcome their problems before they take on Pakistan in the first of three Tests starting at Multan Saturday.
Vaughan, who is in serious doubt for the first Test, fell while going for a run and twisted his knee on Monday, a recurrence of an injury which forced him to have an operation two years ago.
Vaughan also hurt the same right knee last year and had to miss the Lord's Test against New Zealand.
England team management said they are comparing the scan of the latest injury with the one Vaughan had last year and would announce later on Tuesday a final decision on his participation in the first Test.
Vaughan may miss the entire series if his scan reveals a muscle tear, the team management said on Monday.
In contrast, Vaughan's counterpart for the A-team Hasan Raza had a field day to give his side to a comfortable win which will also hearten the senior team.
Raza celebrated his recall to the senior team with a punishing unbeaten 71 as he led his side's pursuit on an easy paced wicket.
Raza, included in Pakistan's 16-man squad for the first Two Tests, hit four boundaries and three towering sixes.
He was ably assisted by another youngster Shahid Yousuf, who hit a brilliant 57 and added 129 for the fourth wickets with his captain. Both batted confidently after Pakistan 'A' resumed the day on 31-1.
Night-watchman Shahid Nazir set the tempo with an aggressive 43, hitting two sixes and three boundaries to unnerve the English bowlers.
Nazir was allrounder Andrew Flintoff's first of three wickets for a cost of 67.
SCOREBOARD
ENGLAND (1ST INNINGS): 126 (Mohammad Asif 7-62) and 256 (Paul Collingwood 61, Andrew Strauss 56; Mansoor Amjad 5-97)
PAKISTAN 'A' (1ST INNINGS): 138 (Hasan Raza 34; Matthew Hoggard 4-39)
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Pakistan 'A' (2nd innings):
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Imran Farhat not out 37
Taufiq Umer c Jones b Hoggard 15
Shahid Nazir b Flintoff 43
Faisal Athar c and b Flintoff 8
Shahid Yousuf lbw b Flintoff 57
Hasan Raza not out 71
Extras: (LB-6, NB-9) 15
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Total: (for 4wkts) 246
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Fall of wickets: 1-27, 2-98, 3-103, 4-232
Bowling: Hoggard 8-1-50-1, Harmison 13-5-40-0, Flintoff 10.2-0-67-3, Giles 9-1-41-0, Udal 9-0-34-0, Collingwood 3-1-8-0
Overs: 52.2
Note: Farhat retired hurt at 69-1 with his personal score on 24 and returned at 232.
Result: Pakistan 'A' won by six wickets
Umpires: Mian Mohammad Aslam and Salim Badar