That tops the 17 million dollar opening day for Transformers: Dark Of The Moon.
It also beats the 18 million dollar haul that Avengers Assemble took in over its first two days in China last year.
Since it began rolling out overseas last week, Iron Man 3 has climbed to 307.7 million dollars worldwide. That's just a few million dollars shy of the international total Iron Man 2 pulled in over its entire run.
The film launches in US cinemas with early screenings ahead of its official Friday release.