A woman who stabbed a romantic rival to death during a fight at a Richmond park last February was sentenced Wednesday morning to eight years in prison.

Crystal Birden, 33, of Richmond, received the sentence in a Martinez courtroom in connection with the killing of 24-year-old Oakland woman Tiye Rebecca Freeman on Feb. 7, 2012.

Birden, who was initially charged with murder, agreed to plead no contest to voluntary manslaughter in Contra Costa County Superior Court last week in exchange for the lesser sentence, prosecutor William Murphy said.

A murder conviction would have brought a sentence of 15 years to life in prison.

Murphy said Birden and Freeman and been fighting over Birden's husband, with whom Freeman was romantically involved.

According to the prosecutor, the pair got into a physical fight on Feb. 7, prompting Freeman to challenge Birden to a fight later that day at a park in the 300 block of Sixth Street.

When the two women met at the park, Murphy said, the Oakland woman charged the defendant, who then pulled a knife from her sleeve and stabbed Freeman to death.

The prosecutor said Birden's husband, whom the women were fighting over, had a history of physically abusing her, which was taken into consideration in the plea deal.

"It's a tragic case -- two women's lives getting messed up by one man," he said.