Pakistan 304 (Babar 78, Salman 56, Leach 4-140) and 21 for 0 trail England 354 (Brook 111, Foakes 64, Pope 51, Nauman 4-126, Abrar 4-150) by 29 runs
Karachi: Harry Brook's magnificent century helped England to a valuable lead over Pakistan on the second day of the third Test in Karachi.
Brook's 111, his third hundred of the series, pushed the tourists to 354, a first-innings advantage of 50 runs.
England had been 58-3, 98-4 and then 145-5 when Brook was involved in the run out of captain Ben Stokes for 26.
But Brook shared a stand of 117 with Ben Foakes, who marked his recall with 64 after overturning being given out on nine.
Although Brook was lbw to Mohammad Wasim, Foakes added 51 with Mark Wood, while Ollie Robinson and Jack Leach eked out 30 for the last wicket.
Pakistan were given nine overs to survive in the fading light, reaching 21-0 to trail by 29.
England have already won the series 2-0 and are looking to become the first team to leave Pakistan with a 3-0 clean sweep.
Brook only got his chance in Test cricket after Jonny Bairstow suffered a freak broken leg, but has surely made his place secure, leaving England to ponder how to get Bairstow back in the side.
The Yorkshireman has become the first England batter to score three hundreds in his first four Tests, the first to score hundreds in each match of an away three-Test series and his 468 runs is a record for an England batter in an away series against Pakistan.
The run out of Stokes could have derailed Brook. With the captain looking for a third run, Brook started then turned around, leaving both men at the same end.
Stokes, though, gave Brook a thumbs up as a signal to put the incident behind him, which he did with pulls through the leg side, inside-out cover drives and three straight sixes.
Brook reached three figures from 133 balls with a back-foot punch for four off the leg-spin of Abrar Ahmed.
He was eventually trapped on the crease to give Wasim his first Test wicket, departing to a rousing ovation from the travelling England fans gathered above the visitors' dressing room.