FC Dallas (7-2-9) extended its unbeaten streak to eight games, while the Union fell to 4-10-3.
Cunningham scored on a header from the top of the goalies box in the 75th minute for a 2-1 lead. His second goal came on a right-footed shot from 10 yards away. Cunningham entered the game at halftime as a substitute for Eric Avila.
FC Dallas David Ferreira tied the game at 1 on a penalty kick by firing the ball past backup goalie Chris Seitz in the 24th minute. Starting Union goalkeeper Brad Knighton received a red card to setup the penalty kick after he tackled Shea inside the penalty box on a breakaway.
Philadelphias Alejandro Moreno scored in the 9th minute with a header from the top of the goalies box.
(Copyright 2010 Philadelphia Union. Reprinted by permission)