Ferjani Sassi scored the resulting spot-kick and Tunisia were able to keep England at bay until the dying moments.
Captain Harry Kane came to the rescue with two goals, the second a dramatic injury-time victor, as England began their World Cup Group G campaign with a stuttering 2-1 win over Tunisia on Monday (Jun 18).
Earlier in the day in Group G, Simon Mignolet was on the bench for Belgium as they opened up their tournament in commanding fashion with a 3-0 victory over Panama.
Hassen then clawed away Maguire's header but required treatment after a clash with Lingard and would not last much longer.
With Kane twice being denied a penalty after being fouled in the Tunisia area, England looked set to be denied by bad finishing and poor refereeing.
"It's a massive boost, a massive bonus, we kept going".
Portugal vs Spain : We showed character, pride - Hierro
But Portugal coach Fernando Santos gave credit where it's due noting: "I've said it so many times, Cristiano is the best in the world".
England were stung and should have regained the lead before half-time but Stones miskicked with the goal gaping and Lingard hit the post with a chip over Mustapha.
"We played some good stuff and created a lot in the first half".
"There could have been a couple of penalties", said man of the match Kane. They were trying to grab hold and stop us running. But England struggled to finish it off.
Kane - who else? - popped up to break Tunisian hearts and the reaction of those in the BBC Sport studio was priceless.
"If you are here you have to get on board with everything, and I think that's what everybody's done".
England comes into the big tournament as the 12th ranked team in the world, and the top team in Group F of UEFA qualifying, securing 26 out of a possible 30 points and the only team from the group to advance to the World Cup, finishing 8 points ahead of Scotland and Slovakia.