The "Braveheart" star Mel Gibson split from Oksana Grigorieva, the mother of his daughter Lucia, early last year and she went on to accuse him of beating her in a violent domestic dispute.
The Russian singer has been fighting to alter their custody arrangements based on the battery claim ever since and the case returned to a Los Angeles court on Wednesday.
But a lawyer for Mel Gibson was left stunned when Grigorieva's lawyer Dan Horowitz announced to Judge Scott Gordon they were no longer interested in pursuing the domestic violence allegation.
Grigorieva has also had a restraining order against Gibson terminated, according to TMZ.com.
The actor, who recently revealed he was confident he would achieve "some kind of justice" in the custody fight, was sentenced to three years probation and a year of counseling in March after pleading no contest to a misdemeanor for simple battery.