Martinez, Villalba lead Atlanta United to 2-0 win over Union
Brad Guzan had three saves in his sixth shutout of the season for Atlanta (12-4-4).
Martinez scored his MLS-leading 18th goal of the season to give Atlanta a 1-0 in the 58th minute, converting from the spot after Philadelphia goalkeeper Andre Blake conceded a penalty in the area drawn by Miguel Almiron.
Villalba put away a cross by Almiron into a wide-open net to cap the scoring in the 76th. Martinez rolled it to Almiron on the left side of the area, and Almiron – as Blake charged – tapped it to Villalba at top of the 6-yard box for the finish.
Philadelphia (6-9-3) has lost four of its last five overall and is winless, including three consecutive losses, in four games with Atlanta all-time.