The Sounders used a mid-season surge of eight wins in nine matches to rise to the top of the Supporters' Shield standings, but have faded down the stretch to sustain a fourth consecutive defeat for the first time in team history.
Both teams had ample scoring opportunities in the first half as the Sounders best chance of the half came when defender DeAndre Yedlin ripped a wicked strike on goal, but it went straight at FCD goalkeeper Chris Seitz.
FCD forward Fabian Castillo had his club's best chance of the first half when he got free just outside the box just moments before the break, but pulled the shot wide of the right post.
FC Dallas finally got its breakthrough with some set-piece magic in the 65th minute when Michel whipped a beautiful free kick into the box for Matt Hedges to easily nod home.
The hosts put the result away three minutes from time when Michel pounced on a loose ball in the penalty area and fired into the gaping net to clinch the win in head coach Schellas Hyndman's final home match.
10/19 16:31:54 ET