US teen girl floors basketball rival with sucker punch after ‘being ordered to hit her by mom’ (VIDEO)

There is outrage after footage spread of a 15-year-old girl receiving a sucker punch allegedly encouraged by the attacker's mother during a youth club basketball tournament in the Los Angeles Metropolitan Area.

Lauryn Ham was taking part in the competition in Garden Grove, around 35 miles from the center of LA, for SoCal Blaze on Sunday.

Her mother Alice, talking to CBSLA, said that other parents who attended the event heard the mother of the attacker say: "Go and hit her" in relation to her daughter.

The girl, who cannot be named due to her age, did just that – as can be seen in video footage of the incident. 

Running from the other side of the court, Ham comes in to challenge a burly girl much bigger than her for the ball.

The attacker misses her shot, but even though there's not that much in the challenge she falls to the ground, as does Ham. 

As the ball advances up the court and the pair walk towards the action, a parent seems to be heard shouting something along the lines of: "You've got to hit her for it".

The girl then does so with an undefended sucker punch that knocks Ham off her feet.

"Oh my goodness," a separate mother is heard saying, as the referee rushes over blowing his whistle. 

Sharing the video on her Instagram page, Alice Ham wrote: "THIS… this right here makes me SICK to my stomach. This happened to MY DAUGHTER at her game yesterday," in the caption.

"There is absolutely no place for something like this in basketball, I don’t care how famous you are!!

"This mom told her daughter to 'go and hit her' and my kid gets an unprovoked sucker punch. I’m sorry but it’s everything that’s wrong with youth sports.

"The girl and her mom showed absolutely no remorse and offered no apology. Youth sports needs to change," she demanded.

To CBSLA, Ham added: "When I saw the clip I was horrified just like everyone else, and so angry. The mom basically incited violence against my daughter, she told her daughter to go and hit her and to me that rises to the level of assault."

Filing a police report against the attacker – who played for the Dream Academy and according to some reports is the daughter of an ex-NBA player – and her mother, Lauryn Ham suffered a bruised neck and concussion.

Alice Ham hopes her daughter can play again one day. 

"I’m just praying she’ll get back on the court and do what she loves," worried Alice.

Garden Grove Police are reportedly investigating the matter, but it is unknown whether charges will be filed.