The winger doubled City’s advantage before the break in what could be a hugely significant result in the WSL title race.
Gareth Taylor’s side had taken the lead just after the 20-minute mark through an impressive long-range effort from Filippa Angeldahl before Hemp’s vital contribution at the Academy Stadium.
After Chelsea had failed to clear Chloe Kelly’s lofted cross into the box, Laura Coombs reacted quickest to the loose ball.
With her back to goal, she knocked the ball back into the path of Hemp who, after quickly sorting her feet out, unleashed an unstoppable first-time volley into the top corner and past the despairing dive of visiting stopper Ann Katrin-Berger.
It was just rewards for the winger, who had braved an ear infection to put in a typically tireless display and help her team over the line at the Academy Stadium.
And Hemp’s sumptuous strike has since gained recognition by being nominated for March’s Goal of the Month award.
The England international is up against Rachel Daly, Beth England, Caitlin Foord, Sam Kerr, Celin Bizet and Rachel Rowe.
Voting closes at 10:00 (UK) on Monday 3 April. Cast your vote by clicking here.