Whilst there's implications of Pan possibly being above Boo in power, those implications are vague to say the least. The most solid evidence we have is the anime presenting her as stronger than Base Goten, but not seemingly by a huge amount, and Goten is described as having not made "explosive growth" in those 10 years according to the Daizenshuu. All that said, there's no way Pan is winning this even taking into account the high-end interpretation of her power when she lacks the experience to counter Boo's abilities.