The San Jose Earthquakes ended the Texas side's unbeaten start to the season, while FCD's in-state rival took a beating on the road
Dallas' unbeaten start to the MLS season was ended, while the Houston Dynamo were thrashed on Saturday.
An 81st-minute goal from Jahmir Hyka saw the San Jose Earthquakes to a 1-0 win which marked Dallas' first defeat.
Hyka's goal was a stunner as he jumped to take a touch over a defender before calmly placing a finish in off the post.
Dallas' loss – the first Oscar Pareja's men have suffered through 10 games – left them third in a Western Conference which saw its top three teams beaten.