Sergey Kovalev Accuser Sues For $8 Mil, You Beat Me & My Dog

7:28 AM PT -- The accuser's attorney tells us his client is suing for $8 million.

The woman who claims she was attacked by boxing superstar Sergey Kovalev has now filed a lawsuit against the Russian ... claiming the 35-year-old also brutalized her dog.

It's all in court docs obtained by TMZ Sports ... Jamie Frontz (who has identified herself publicly) claims she met Sergey at the grand opening of a boxing gym in Big Bear, CA back in June.

Frontz -- a model and actress -- claims Sergey and a friend followed her home from the party and Kovalev aggressively tried to have sex with her.

"At one point, Kovalev pinned Jamie to the couch, leaning over her with his hands on either side of her shoulders, such that she could not move away."

Jamie claims her dog sensed the danger and tried to intervene -- but Kovalev shoved the dog away and then kicked it in the chest.

While tending to her dog, Jamie claims, "Kovalev turned to [her] and punched her with full force directly in the face one time with a closed fist."

In her suit, Jamie claims Sergey fled the scene -- so, she called the cops.

TMZ Sports broke the story ... cops tracked down Kovalev and arrested him. He's been charged with felony assault and faces up to 4 years in prison. Kovalev has pleaded not guilty.

In her suit, Jamie claims she went to the emergency room where she was treated for a broken nose, head injuries and a concussion. She also suffered severe back and neck injuries.

The next morning, Jamie claims she saw Kovalev crawl out of the bushes near her cabin, and he yelled her name -- so, she called 911 and later got a restraining order against him.

Jamie is suing for more than $3 million in damages.

We reached out to Kovalev for comment -- so far, no word back.

Sergey is due back in court in March to face the criminal charge. He's also set to fight Eleider Alvarez this Saturday, in a rematch of an August bout that he shockingly lost.