Robert Lewandowski put Poland ahead with an expert control and finish, his 76th international goal, but Axel Witsel levelled from outside the box.
Kevin de Bruyne made it 2-1 before Leandro Trossard struck twice, the second a beautiful curling shot.
Leander Dendoncker hammered in from 30 yards and Lois Openda scored four minutes after coming off the bench for his international debut.
It was a perfect response for Roberto Martinez’s side, who lost 4-1 to the Netherlands in their opening game.