Lauren Hemp scored a first-half double while Jill Scott, Georgia Stanway, Ellen White and Chloe Kelly got on the scoresheet, as well as Natalie Haighs own goal.
It was a much-changed team for City, who were without several players, while Alan Mahon took charge with Gareth Taylor isolating at home.
With less than two minutes on the clock, Hemp netted from close-range after getting on the end of a Kelly cross.
Villa had a chance of their own soon after when Nadine Hanssen fired wide from inside the box and it wasnt long before Kelly hit the post for City.
The hosts doubled their lead in the 17th minute when Scott headed home from Lucy Bronzes cross and the Best FIFA Womens player assisted Stanway with the third.
Hemp had her second in the 38th minute when she headed home from a Kelly corner, before Haigh bundled home and White sealed the sixth just before the break.