Coach Jonathan Morgan made five changes to the starting XI which was beaten by Durham last weekend, but the Foxes were behind after three minutes in Sheffield.
It came about in strange circumstances as Sophie Barker’s corner flew through a crowd and into the net, ricocheting off the far post, to hand the hosts an early lead.
Leandra Little, meanwhile, struck the woodwork for the hosts, before Katie Wilkinson converted from close range to extend the lead for the Blades.
Wilkinson swiftly netted her second of the game and Aimee Palmer scored a fourth for her side from the edge of the area shortly before a first-half drinks break.
With seconds of the opening 45 minutes to go, United extended their lead to five as Veatrikki Sarri stepped up to calmly slot a penalty beyond Taylor Charlton.
Following the interval, City's women began to test the home defence more often, but the Blades continued their goalscoring exploits nonetheless.
Olivia Fergusson scored a sixth, following a neat through-ball from Palmer, before the Manchester United loanee curled in a seventh of the afternoon with an free-kick.
It was Leicester who had the final say, however, with Lachante Paul curling in a fine effort from the edge of the area to register on the scoresheet late on.
The details...
City: Charlton, James, Morgan, Nuttall (Brown 46'), Johnson, Thomas (Smith 46'), Everett, Jhamat (Cataldo 71'), Dugmore, Blanchard, Paul
Subs not used: Moncaster, Bailey-Gayle, Taylor, Popple
Goal: Paul 73'