Shoaib Malik advanced to 245 as Pakistan piled on the runs in Abu Dhabi, but England avoided any early setbacks in reply.
England's new-look opening partnership passed its first examination after Shoaib Malik's career-best 245 had lifted Pakistan into a dominant position on day two of the first Test in Abu Dhabi.
In his first Test appearance for more than five years, Shoaib advanced confidently from being 124 overnight to post a record score at the Sheikh Zayed Stadium and the third-highest total by a Pakistan batsman against England.
Shoaib also shared a record fifth-wicket stand of 248 with Asad Shafiq (107) across two wicketless sessions, before a flurry of dismissals hastened a declaration from Pakistan at 523-8.
However, there was a welcome lift for England as Moeen Ali (15 not out) - at the top of the order in Tests for the first time - and Alastair Cook (39 not out) survived a couple of early scares to take the tourists to 56 without loss at stumps.
England still have much work ahead if they are to avoid defeat, having been significantly punished for handing let-offs to Shoaib, Shafiq and Mohammad Hafeez (98) on day one.
A solid start with the bat on a seemingly lifeless pitch will at least provide optimism, though, particularly as Pakistan have been weakened by the absence of their leading spinner, Yasir Shah.
England's slow bowlers, Moeen and leg-spinner Adil Rashid, were unable to make any impact - the latter returning dismal figures of 0-163 to sit second behind Devon Malcolm in terms of the most runs conceded on England debut.
There was no sustained threat from any bowler as Shoaib and Shafiq cruised through the morning session, before upping the pace on their way to personal landmarks in the afternoon.
Shoaib steered James Anderson (2-42) through gully for two to bring up his maiden Test double-hundred in the 135th over and there was further cause for celebration three balls later when a swept four off Rashid took Shafiq to three figures.
England's plight was summed up by seam-bowling all-rounder Ben Stokes sending down an over of experimental off-spin prior to tea.
Yet as Pakistan looked for further acceleration in the evening, Stokes was able to strike in three successive overs with his usual fast-medium offerings.
Shafiq was lbw to an off-cutter from Mark Wood (1-58) before Stokes had both Sarfraz Ahmed (2) and a cramping Shoaib caught by Ian Bell - the man guilty of dropping Hafeez and Shafiq on Tuesday.
When Zulfiqar Babar fell for a duck, Pakistan opted to declare with Stokes boasting admirable figures of 4-57.
Cook almost played on to the second delivery of the reply and a cautious Moeen survived a review for lbw when facing Rahat Ali in the fifth over, but there was little else to concern England's openers.