The winger was joined in the starting line-up by City team-mates Alex Greenwood and Chloe Kelly with Khiara Keating, Ellie Roebuck, Esme Morgan and Jess Park on the bench.
Hemp almost fired the Lionesses ahead in the opening minutes at the King Power Stadium but her effort was clawed away by Belgium keeper Nicky Evrard.
But the England star smashed in the opener in the 12th minute. Millie Bright headed Kelly’s corner against the post and Hemp was quickest to react, firing in the loose ball.
She went close to a second after the break with a driving run down the right wing but her low shot was kept out by Evrard.
Park replaced Kelly with seven minutes remaining and almost created a second with a wonderful dribbling run late in the game.
Sarina Wiegman’s side face Belgium again on Tuesday when they travel to Leuven.
Netherlands remain top of Group A1 on goal difference following their 4-0 victory over Scotland with Jill Roord starting in midfield for the Dutch.
Elsewhere, Filippa Angeldahl started for Sweden as they beat Switzerland 1-0 in Gothenburg.
And Laia Aleixandri helped Spain keep a clean sheet before Jenni Hermoso’s 89th minute goal secured a 1-0 win away to Italy.
