The goal took a lot of the sting out of England's challenge, and although they dominated possession after the break, their attack was missing the thrust of the first half.
And 10 minutes before half-time England were punished for wasting chances as Roldan ruled Walker had intentionally made contact with Ben Youssef, Sassi's penalty powerful enough to beat the fingertips of Jordan Pickford and find the bottom-left corner.
"They created so many chances".
England almost scored in the opening minutes, beating Tunisia's high line over the top with a direct ball from the back.
Tunisia couldn't hold on for much longer with Harry Kane tapping home after Hassen made a stunning save from John Stones' header. Despite the result, their sloppiness before will concern Southgate. With fellow African teams Morocco, Nigeria and Egypt all losing their opening games in Russia, Maaloul conceded that Tunisia were feeling the heat.
Hello good evening and welcome to the last game of the day at the ongoing FIFA World Cup in Russian Federation. But at this stage, England simply do not have the players capable of taking a grip of the game and calming their teammates when they are losing momentum.
Then Kane came to the rescue in stoppage time.
England's players later thought they deserved a similar call when Kane was brought down in the opposite penalty area, but the referee disagreed.
Holding, shirt-tugging and grappling at set-pieces has become an increasing problem in the game in recent years, and one that Federation Internationale de Football Association has attempted to eradicate.
Twice wrestled to the ground during the match, England captain Harry Kane finally evaded the Tunisian defence just as time was running out.