England 7 for 1 trail Pakistan 304 (Babar 78, Salman 56, Leach 4-140) by 297 runs
Karachi: Rehan Ahmed took important wickets as England bowled out Pakistan for 304 on the first day of the final Test in Karachi.
Leg-spinner Ahmed, at 18 years and 126 days the youngest man to play a Test for England, grew from a nervous start to claim 2-89.
Ahmed had Saud Shakeel caught at short leg to break a fourth-wicket partnership involving Pakistan captain Babar Azam, who was later crucially run out for 78.
When Ahmed had Faheem Ashraf leg before with a magical googly, Pakistan, who won the toss, had been reduced to 237-7.
Salman Agha and the recalled Nauman Ali fought back in a stand of 48 before Nauman skied a catch off Jack Leach.
Salman continued to counter-attack before being stumped for 56 off Leach, who ended with 4-140.
On a pitch that looks set to turn more and more, England lost Zak Crawley to the fifth ball of their reply and closed on 7-1, trailing by 297.
England already hold an unassailable 2-0 lead in the series and are looking to become the first team to leave Pakistan with a 3-0 clean sweep.
This was a historic day before a ball was bowled. Ahmed, with his father by his side, was presented with his England cap by former captain Nasser Hussain to break a record held by Brian Close since 1949.
At the other end of his career, Azhar Ali was recalled in one of four changes to the Pakistan side - the batter playing his final Test after announcing his retirement on Friday.
All of the pre-match talk was about how much the pitch might turn. Indeed, Leach became the first spinner to open the bowling for England in the first innings of a Test since 1921.
The assistance for the spinners took time to arrive - the surface looked suited for batting for much of Saturday.
Such conditions seemed dangerous for England with James Anderson rested, Ollie Robinson struggling with illness, Mark Wood only used in short bursts and the callow Ahmed on debut.
Aided by some Pakistani mistakes, however, England used the creativity and determination that has become a trademark under captain Ben Stokes to work their way through the home batting.
Still, the size of England's batting task both now and in the final innings of the match was highlighted by Abrar Ahmed straightening a delivery that trapped Crawley on the back foot.