The Roos went down to the Bombers by 39 points at EtihadStadium on Friday night, but the margin didn't accurately reflect Essendon'sdominance.
The Bombers smashed North in possessions (449-291), marks(159-73) and, most concerning for North coach Brad Scott, clearances (52-30)and stoppages (35-21).
Scott described his team's performance as "horrific"and Thompson did not disagree when he spoke with AFL.com.au after the match.
"We've had a great pre-season so to bring up aperformance like that is very disappointing," Thompson said.
"We're ashamed of it obviously, it's pretty hard.
"We know what we've done wrong already and we'll workon that at training."
Thompson acknowledged North's ball movement had been poor attimes against the Dons, but said its chief failing had been its inability towin possession.
"We just couldn't get our hands on it. We couldn't winthe contested ball and that's what we're known for, so we're prettydisappointed with that," Thompson said.
"You've got to have the ball to move it and we didn'thave our hands on it a lot.
"It all started with the contested ball. We were down alot in that and have got to get that right first."
Thompson said North had been expecting Essendon to play thehigh-possession game style it employed on Friday night, but had simply beenunable to combat it.
The Roos now have nine days to lick their wounds beforetheir round two clash with the Western Bulldogs at Etihad Stadium next Sunday.
Thompson is confident that will be more than long enough forhis team to rediscover their ball-winning ways.
"It's pretty easy to turn around I think. With anine-day break we've just got to get our drive back," he said.
"I'm talking about contested ball so much. We were downa lot on that.
"If we start winning the ball, teams have to startworrying about us, not the other way around."