Houston came from behind twice to get back to level terms but it was a stoppage time winner that sent them to another loss.
Spirit started early and they had an early lead as Jodie Taylor put pressure on the keeper which lead to a poor clearance, sending it right to Diana Matheson who controlled with her first touch before chipping the keeper with her second.
But within 10 minutes Houston were level as Nina Burger send a ball out to Ella Masar on the right, enabling her to cross in to Kaylyn Kyle, making a run in to the area. After controlling the ball Kyle squared back for Burger who scored her first ever Dash goal.
Houston kept on attacking and in the 21st minute they thought they had the lead as Kika Toulouse which Burger headed home but was denied after an offside flag.
In the 26th minute Becky Edwards got through the Washington defense and found Masar only for her shot to be blocked by Ashlyn Harris.
In the 38th minute Spirit took the lead again as Christine Nairn hit a long ball that was recovered by Jodie Taylor clear of the Dash defense, allowing her to control and finish.
It was all Washington through the rest of the half as they managed to hold out easily through to half time with the 2-1 lead.
Spirit were by far the more likely team as they kept on pushing for a goal, managing 17 shots, not content to sit on a 2-1 lead.
After being under the pump for much of the second half, Houston got back on to level terms in the 77th minute as Stephanie Ochs, came back to haunt her former team as she sent in a corner for Osinachi Ohale who headed home the equalizer.
Spirit had a golden opportunity just five minutes after the equalizer as a foul from Erin McLeod allowed Matheson to step up to the spot, but was denied as McLeod made the save.
But in the 93rd minute McLeod was beaten as Christine Nairn gained possession from 30 yards out, allowing her to put a powerful shot up out of the reach of McLeod to seal the win.