"This is not how I raised my daughter," Benjamin said.

TMZ Sports published video earlier this week showing Benjamin's teenage daughter flattening her 15-year-old opponent with a haymaker for seemingly no reason during a basketball game in southern California on Sunday.

Alice Ham, the mother of the girl who was punched, tells us her daughter sustained a concussion as a result of the punch.

The former 1st round draft pick in 1998 -- who played 4 seasons in the NBA, averaging 5.5 points for his career -- spoke to NBC LA ... and it's clear the former hooper knows his daughter really screwed up.

"To the young lady who was punched by my daughter during a youth basketball game, I sincerely apologize to you and I am praying for your complete healing both physically and emotionally," Benjamin said.

"To her family, I deeply apologize and regret that this happened to your daughter as she did not deserve this to happen to her. Finally, I apologize to all of those who have been impacted and hurt by the actions of my daughter as well as those of her mother. I am here for your family and wish only the best for you."

It's interesting ... Corey also said sorry for the mom of his daughter ... who is seemingly heard on video directing her kid to hit the 15-year-old just seconds before the attack.

Corey continued ... "As a father, I'm shocked and disappointed at my daughter's behavior as this is not a reflection of the values and standards that my family holds. Nor does it exemplify the values, character and spirit of sportsmanship that the game of basketball requires."

"My daughter made a mistake. One that she will need to make right. I am committed to getting my daughter any help she may need and support her in taking accountability for her conduct."

But, the apology from Corey might not be enough ... 'cause Ham has lawyered up, hiring attorney Kevin Hahn.