England winger Kelly curled in a superb opener from outside the box in a first half the FA Cup finalists dominated.
Kelly doubled the lead from the spot after half-time before United States midfielder Sam Mewis quickly netted her second goal in four days for the club.
Ellen White headed in a fourth and Anna Filbey flicked in a late Spurs goal.
What a moment of bliss for all Manchester City women and fans. We keep the record! We make things happen!
Watch full highlights here-