Having conceded a 146-run first-innings lead, England collapsed to 160 all out second time round, failing to recover after Umar Gul had wrecked their top order with a three-wicket burst.
Pakistani opener Mohammad Hafeez alone scored the 15 runs his team needed to complete the formality of victory.
"We did not expect it to be so easy for us...a wonderful performance from the team, especially Saeed Ajmal... his seven wickets in the first innings put us on the way to victory," Pakistan captain Misbah-ul-Haq said in a pitchside interview.
England were shot out for 192 in their first innings and in the second, Jonathan Trott (49) was the lone top-five batsman to reach double figures. Gul took four for 63 while off spinner Ajmal claimed three wickets to complete his second 10-wicket test haul and earned himself the man of the match award.
Left-arm spinner Abdur Rehman also chipped in with three second innings wickets.
"He's been a matchwinner for us for a longer period of time," Misbah said of Gul. "Whenever we need him he bowls his heart out."
England captain Andrew Strauss made no excuses for England's feeble efforts with the bat.
"All credit to Pakistan, I thought they played exceptionally well. Once they got ahead of us in the game they did not allow us back in," he said.
"I thought our bowlers did a pretty good job but in both innings our batsmen should have done better so we need to learn a lesson from it. We won't be panicking and we'll come back strong in the second test."
Gul, who went without a wicket in England's first innings, mowed down the top order on Thursday, starting with Strauss, who departed for six runs after a controversial dismissal.
Umpire Billy Bowden adjudged Strauss caught behind down the leg-side even though hotspot revealed no trace of the ball touching his bat or thighpad. The opener opted for a review but could not overturn the decision.
There was no such confusion about fellow opener Alastair Cook (five), who meekly gloved a Gul delivery, again down the leg side, to depart caught behind.
Gul struck another huge blow when he banged it in short at Kevin Pietersen, who could not resist temptation and holed out to deep square leg as England slumped to 25 for three.
Spinners Ajmal and Rehman then joined the party.
Ajmal trapped Ian Bell (four) leg before, a decision that was reviwed in vain, and Rehman dismissed Eoin Morgan (14) as England lost the top half of their batting order for a paltry 74.
Trott looked largely unperturbed and hit six boundaries before abandoning his usual restraint and chasing a wide Gul delivery to give Adnan Akmal his fourth catch behind the stumps.
Graeme Swann (39) counter-attacked, hitting a few lusty blows, but his cameo only succeeded in making Pakistan bat again.
The second test starts in Abu Dhabi on January 25.
Pakistan are hosting the three-match series in the Gulf due to security concerns in their own country. The teams are playing for the first time since the controversial and acrimonious 2010 series in England which led to three Pakistan players being jailed for corruption.
