After a near tragedy, custody battle explodes between USHER and his ex after five year-old son almost drowns.

Usher’s ex missus Tameka Foster has filed legal docs requesting emergency custody hearing in the wake of the pool accident that landed their young son, Usher Raymond V, in the emergency room.

As The ENQUIRER previously reported the couple divorce back in 2009  while “The Voice” mentor received custody of their two sons last year.

NBC reported that in filing, Foster's attorney charges that "the children are at risk while in the care of third-party caregivers…while (Usher) travels around the world for his work-related activities.

On Monday, the 5-year-old almost drowned in dad’s pool while trying to retrieve a toy that was stuck in an underwater pool drain.

According to Atlanta police, the child’s arm became lodged in the powerful drain while  underwater.

Panicking, his aunt and  housekeeper unsuccessfully tried to free the terror-stricken child.

Two contractors working inside the house rushed to the pool and were able to free the boy.

CPR was quickly performed by one of the men, reviving the lad before EMTs arrived at Usher's abode.

The emergency custody hearing has been docketed for August 9.