The Fire go down to their perennial nemesis, Dallas and their loss ends an unbeaten 11 game streak, one shy of an MLS record.
Goals from Jeff Cunningham, an own goal by CJ Brown, and Kenny Cooper, gave Dallas an easy, 3-0 win over the Fire.
The second half turned scrappy with 6 yellow cards and Bakary Soumare's 79th minute ejection.
The Fire were coming off a grueling third game in a week which saw them travel coast to coast for matches against the Red Bulls and Chivas and then finally back home to play Dallas. They were also without Cuauhtemoc Blanco called up for national duty. Fire coach Dennis Hamlett also decided to rest standouts Marco Pappa and Gonzalo Segares.
"It's asking a lot to put the same 11 players on the field three times in a week," Hamlett said.
Their weariness showed as they looked a step slower compared to the Dallas players and gave the ball away easily.