Babar Azam’s masterclass and Shan Masood’s resistance helped Pakistan to reach 139-2 in rain interrupted day-one play in Manchester.
Babar and Shan remained unbeaten at the end of the day with 69 and 26 respectively after bad light forced an early close.
The left-handed opener Masood was twice missed on 45 by England wicketkeeper Jos Buttler either side of a lengthy rain break, with off-spinner Dom Bess the unlucky bowler on both occasions.
Meanwhile, the prolific Babar continued his good for in the longest format of the game as he reached half-century in fifth successive innings, with his previous five matches yielding four hundreds.
When play resumed in the early evening after a long rain delay, Root was soon bowling his occasional off-breaks in tandem with Bess to try and keep the match going under grey skies after Jofra Archer had pitched short to Babar.
Pakistan were 43-2 when Babar came in to bat after captain Azhar Ali, who had won the toss, fell lbw for a duck to Chris Woakes.
Babar started cautiously but after the lunch interval he unfurled an array of stylish attacking shots.
He struck express paceman Archer down the ground for four before driving Bess for another boundary to bring up Pakistan's hundred.
Babar drew level on 45 not out with Masood, who was on 22 when the right-hander came into bat, going on to complete an impressive 70-ball fifty, including nine boundaries.
The conditions favoured England's four-man pace attack, who had been involved in last month's 2-1 series win over the West Indies, completed at Old Trafford.
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