The Union picked up their third win of the season with a convincing 3-0 scoreline at Chivas.
Conor Casey scored twice to set the Union on its way. Martin Rivero was called for a handball on an indirect free kick inside his own box, and the big striker dispatched the penalty to make it 1-0 in the 28th minute.
He scored a stunning header in the 66th to bag his second, connecting with a beautifully curled Cristian Maidana cross and powering his effort past Dan Kennedy.
Maidana himself scored the controversial third in the 76th, his hard low shot dummied by the blatantly offside Andrew Wenger.
Philadelphia is now eighth in the Eastern Conference with a 3-7-5 record. Chivas USA remains last in the West on 2-7-4.