No, GDP has a few ways to measure it, China beats the US on some of them: https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(PPP)
I think China is also as much of a *regional* hedgemon as the US.
Might argue the EU as well, the Brussels effect etc., but that's less clear. Even after Brexit, the GDP-PPP is very close to the USA, though it is also definitely behind the USA.