Greg Howes, who came in the game in th 18th minute when former USL-1 MVP Leighton O'Brien went down with a groin injury, led the Sounders with two goals, and they got several great saves from goalkeeper Chris Eylander to preserve the shutout.
Hugo Alcaraz-Cuellar set up Howes for the first goal in the 45th minute, then scored the second goal himself in the 60th minute with a 30-yard strike past Atlanta keeper Ryan McIntosh.
Howes blasted a 20-yard shot that deflected off defender Matt Bobo and left McIntosh going the wrong direction for the third goal with eights minutes to play. Howes would be honored as the Championship Game MVP. Craig Tomlinson closed out the scoring in stoppage time.
"Our objective in the second half was to come out and not give anything away," said Seattle coach Brian Schmetzer. "That was the obvious way to go. If we get the clean sheet, we win, but Atlanta made things very difficult on us in the first 15 minutes of the second half. They put us under pressure and forced Eylander to make some tough saves. The dagger was Hugo's goal. After that I knew we had them."
According to published reports, MLS will award its 15th franchise to a Seattle group that includes Hollywood Joe Roth, Seattle Seahawks and Portland Trail Blazers owner Paul Allen and Adrian Hanauer, managing partner for the Seattle Sounders.
SOUNDERS STARTING XI:
Chris Eylander (23) Won starting job in 2006 out of Univ. of Washington.
Taylor Graham (27) Stanford product has played in MLS with Kansas City and New York
Danny Jackson (27) Englishman won NCAA title at Univ. of North Carolina.
Kevin Sakuda (27) Former Duke player is in his fourth season with Sounders.
Zach Scott (27) Hawaii product has played six years in Seattle.
Kenji Treschuk (24) Hawaiian played as an amateur in the Netherlands after finishing at Penn State.
Leighton O'Brien (31) Has played in MLS (San Jose and RSL) as well as in Sweden.
Josh Gardner (24) Signed with Sounders in March after three years with L.A. Galaxy.
Hugo Alcaraz-Cueller (30) Mexican-born playmaker previously played for Portland Timbers.
Sebastien Le Toux (23) USL-1 MVP's previous experience was in French Second Division.
Roger Levesque (26) Former Stanford star has 32 goals in five seasons with Sounders.