Harley Quinn defeats Batman, Wonder Woman and Superman all at once (it's a very low showing for them). By grabbing WWvs lasso from her thigh, trying Batman up and forcing him to tell her where's his Kryptonite Ring in his utility belt. Then she pulls it out and Superman is instantly incapacitated.
WW does nothing, only helplessly stands and watch. Superman also was doing nothing before Harley has pulled out a Kryptonite Ring.