Cris "Cyborg" Justino was cited for battery for punching UFC fighter Angela Magana in the face at a UFC fighter retreat in Las Vegas this weekend ... TMZ Sports has learned.

According to the Las Vegas Metro Police narrative, Magana says Cyborg punched the left side of her face after the two fighters got into a verbal argument. Police say they reviewed surveillance video that showed Cyborg throwing a punch, hitting Magana in the face once.

According to officials, witnesses jumped in and broke up the fight.

Cops say Magana -- a 33 year old UFC strawweight -- transported herself to the hospital and was treated. According to the narrative, a doctor at the hospital diagnosed A.M. with an "acute head injury, cervical strain, and laceration of the lip."

She returned to her hotel room and called cops.

Magana told police the fight sparked over comments that were made on social media.

Since the incident, A.M. has gone on a Twitter rampage against Cyborg ... "I was the victim of roid rage today. Hope it was worth your job. Sue happy lawyers hitting me up left and right now #Cyborg"

Cops say they also spoke with UFC fighter Bec Rawlings ... who verified Angela's story.

Police made contact with Cyborg, but she did not want to give her side of the story. She was cited for battery and will have to appear in court.

Cage Pages obtained video of the incident.