Cecilia Braekhus Down For Superfight With Claressa Shields!

Getchya popcorn ready for the biggest boxing match in women's history ... 'cause Cecilia Braekhus tells TMZ Sports she's down for a superfight with Claressa Shields!!!

"I wanna be in a ring with that," Braekhus says.

Of course, Cecilia and Claressa are considered the two best female boxers on the planet -- Cecilia is 35-0 while Claressa is 9-0 -- and Cecilia says she's willing to duke it out in the ring to see who's No. 1.

The only problem??? The two are in totally different weight classes -- Claressa has about 13 pounds on Cecilia -- but Braekhus tells us she'll come up in weight if Claressa will go down.

"It's three weight divisions between us," Cecilia says ... "So, that issue needs to be resolved."

The good news??? Claressa says she's willing to meet Cecilia in the middle ... 'cause she just told us this week she'll fight the boxing superstar at 154!!!

So ... LET'S GET IT ON!!!!!