EXCLUSIVE

MMA fighter Josh Copeland -- who just fought (and lost) in the $1 MILLION match at PFL 11 -- was arrested for domestic violence after allegedly punching his wife so hard in the face, he left her bloodied and bruised.

It's all detailed in the police report obtained by TMZ Sports ... law enforcement in Adams County, Colorado raced to the couple's home on Feb. 2 after reports of an attack.

When they arrived at the home, Copeland's wife had "an obvious bruise on her left eye, a cut and was bleeding. There was blood down the front of her face and neck."

Copeland's wife said the two had been arguing -- when 36-year-old Josh pushed her so she pushed him back.

The two continued to attack each other -- with Copeland's wife admitting she slapped him in the face multiple times.

Finally, Copeland's wife said the 6'1", 265-pound fighter "then punched her in the face" and threw her on the bed. She says Copeland also took her phone so she couldn't call for help. Cops say they later found her phone in Josh's pocket.

Cops say Josh had redness and blood on his face -- but did not remember punching his wife.

Copeland's wife was transported to a nearby hospital. Josh was arrested and booked for second-degree assault, obstruction and child abuse ... since the whole incident allegedly took place in front of their child.

Copeland is due back in court next week.

Copeland is 18 and 6 as a pro-MMA fighter -- and even had a stint in the UFC in 2014 and 2015.