He also gave Temari a run for her money, but Lee still has this one.
First off, that was a filler. (a ridiculous one at that)
Second, she wasn't even going for the kill the entire time, while Konohamaru was giving it his all.
Third, she limited her use of wind jutsu.
If she wanted to, she could have cut him into little pieces at the start, but she decided to humor him and herself.