"We knew it was a mathematical possibility but I can tell you what – I certainly don't get up and bounce out of my house and think 'let's win by 100 points'," Lyon said after the Saints dispatched the Bombers by 108 points.
"I come to AFL games knowing that if you don't compete and you don't chase and tackle, you get embarrassed very quickly. To be frank, it was the furthest thing from my mind until it became a possibility, but I can understand everyone being excited, and at the end there was a fair bit of buzz.
"You could hear the crowd and it becomes real, so when an almost impossibility becomes real everyone gets excited. But we've got to move on pretty quick, don't we?"
Despite being on track early to record a huge win at Telstra Dome, Lyon said the focus had remained on just beating the Dons until late in the match.
"It certainly wasn't a focus at all pre-game, at quarter-time or half-time," he said.
"The only thing that happened at three-quarter time was we spoke about [it]. We hadn't focused on any prizes – top four or top eight – we've just been all about how we want to improve our footy, but I did say 'look, if you continue in this vain, that mathematical possibility is there'.
"Why we got ourselves in this position is because we were about the contested ball, our ball movement, our defensive work and our chase and tackle."
The Saints have now booked a qualifying final showdown with a Geelong side in ominous form.
"It's the biggest challenge in football, but we've earned the right to be there and we're excited about trying to play our best footy against what's (been) proven to be the best team in the competition," Lyon said.
"What I would say is that we've improved our football. How you measure confidence, I don't know. Confidence is a result of actions; at the minute our actions are making us competitive in most AFL games we play in."
Lyon, who remarked he had "22 season-defining games" this year, maintained he derived no greater satisfaction at the top-four berth given the fact his side had been roundly written-off earlier in the season.
"You can only look at the results of the weekend to show what a relentless industry it is," he said.
"If you slip up, you get hurt. Sometimes some of the criticism is accurate and sometimes it's inaccurate, so what I do is I filter it out. I respect those that I respect, and the other ones you drop in the bin and move on."
Sean Dempster will play no part in the finals campaign after rupturing an anterior cruciate ligament in the opening minutes of the game. Lyon said he remained "hopeful" Luke Ball would be available to return to the side as a replacement.
