Lakers coach Luke Walton, point guard Isaiah Thomas and Pelicans point guard Rajon Rondo had all been ejected by halftime.
By then the Pelicans had also taken a commanding lead by exploiting the Lakers' suddenly backsliding defense in a 139-117 victory.
With the loss, the Lakers fell to 23-33 while the Pelicans improved to 31-26.
Rondo and Thomas both played for the Boston Celtics, with one difference — Rondo won a championship and Thomas led the Celtics to the conference finals.
Walton's ejection came with 1:38 left in the half when Kyle Kuzma was called for a foul after he thought he made a clean steal.