Chris Rock is stepping up to the plate - or, should we say, the test tube - to determine whether he's the father of a 13-year-old boy.

Last month, Kali Bowyer, 35-year-old freelance journalist, filed a paternity action in Georgia Superior Court.

"I'm not asking for money for myself," she tells us, "nor am I suing him for $1 million. I'm just seeking a DNA test to establish paternity, medical coverage, child support."

Rock's lawyers say he's willing to do the test, but he has been busy promoting his new movie, "I Think I Love My Wife."

Bowyer is getting impatient. She says she talked with a lawyer for Rock soon after the birth of her son, Jordan. But she admits she let the paternity issue drift because she never expected the then-unmarried comic to be part of the boy's life.

"Chris and I were part of the same group of friends," she says. "I wouldn't even call it dating. We were two consenting adults who had sex once in a while. No strings attached."

Bowyer says she got back in touch with Rock's lawyer after Jordan had a grand mal seizure. She says she's in debt and doesn't have health insurance.

A source close to Rock says the time of her suit "smells opportunistic," adding, "She acknowledged [after Jordan's birth] that she'd had other sex partners. Chris has never refused her requests."

Bowyer says she wants to protect Jordan just as Rock protects his daughter with wife, Malaak: "If his child was sick, he'd be knocking down doors."