It's really close, I can't tell between lee and Sakura, if lee picks up the 6th or 7th gates tho I think he takes it. Ppl act like Sakura's healing gives her an automatic win but I don't know, Lee can inflict an enormous amount of damage really quickly, one thing that could happen is him inflicting more damage than her seal can heal at a given time, as it's not an instant process and lee can cause traumatic injury with one blow. Lee also could just flat out run her reserves dry from all the constant healing if it can keep up. 8th gate was enough to take on a juubi jin. Sakura would have a terrible time fighting gated Lee from part 1, imho. The combination of speed and power is too much and the 8 gates is one of the most op things in this manga. Sakura is a phenomenal support nin but Lee with the gates just has WAY more potential than Sakura.