Pakistan, who have lost 13 of their last 18 Tests, struggled in the difficult batting conditions after Root won the toss and were dismissed for just 171.
Robinson removed four of Pakistan's top five batters with his movement off the seam, ending up with 5-51, while Tongue shot out the tail with his pace to finish with 5-46.
Asked which of the bowlers was keeping the match ball, Tongue revealed after the close of play that it was being shared — literally.
"The groundsman has kindly split the ball in half so I'm sure I'll be able to get that mounted somewhere at home!" said Tongue, who claimed his fourth five-wicket haul in his 13th Test.
"It's crazy — it's the first time I've seen that happen."
With England reaching 2-112 at the close on Wednesday, it was the most satisfying days for Root, back as captain for a second stint after the international retirement of Ben Stokes, as he ended up unbeaten on 37 at the close.
Robinson made an instant impact after Root put the Pakistanis in, trapping Azan Awais lbw with the opening delivery of the innings.
Remarkably, it was the first time a wicket had fallen to the very first ball of a series in England, where matches have been hosted since 1880.
It has only previously happened 11 times on any ground in the history of Test cricket.
Jimmy Anderson was the other English player to do it, when he removed Dean Elgar in a series in South Africa in 2019-20.
When Robinson, who missed the last two Tests of the New Zealand series earlier this summer with a knee injury, removed Shan Masood lbw in the fifth over, Pakistan were reeling at 2-6.
Imam-ul-Haq and Abdullah Shafique steadied the ship either side of a rain delay with a partnership of 91 but Tongue removed Imam to a good, low catch at second slip by Harry Brook for 42 and Shafique fell for 61 to Robinson to put England back on top.
Pakistan's stand-in captain Salman Ali Agha and Ali Usman then went in successive balls to the pace of Tongue and the tourists' tail was quickly polished off with the last five wickets falling for 21 runs.
England lost Ben Duckett for 15 to the probing Mohammad Abbas – the sixth lbw dismissal of the day – and fellow opener Emilio Gay, who edged Mohammad Ali to Agha at slip for 33.
But an unbroken stand of 64 from Root and Jordan Cox saw England through to the end of play as the home side came out fast in their attempt to win a first Test series since December 2024.
