The Saints were outstanding at Marvel Stadium, first grinding down Fremantle in a dour first half and then kicking clear to win 14.10 (94) to 5.3 (33).
They kept the Dockers to just five goals under the stadium roof after conceding at least 100 points in each of their last three losses.
After the 61-point triumph, they now face the Blues next Friday at the MCG in a game certain to attract more fans than the 20,000 who witnessed them take apart the Dockers.
"We're not a 'get carried away' group and I'm not a 'get carried away' coach - good or bad," Lyon said.
"Last week, we didn't beat anyone up (after losing). This week, we're not over-celebrating. Either way, that's dangerous."
The Saints kept star Fremantle midfielders Caleb Serong and Andrew Brayshaw to less than 20 possessions. Serong's 15 were the lowest since his debut 2020 season.
Meanwhile, St Kilda midfielder Jack Macrae was best afield with 38 disposals.
But Lyon said there was no specific job, noting their usual tagger Marcus Windhager spent most of the game on a wing.
"He (Macrae) didn't have a role on him (Serong) ... and Jack (Steele) didn't really have a role on Brayshaw. They just went head-to-head," Lyon said.
"But there was probably some good opponent-responsibility and decision-making.
"We didn't even tag."
Lyon was seen smiling when Hugo Garcia kicked a goal in the last quarter.
Garcia was subbed out of the game early in the second term of last week's loss to Brisbane as Lyon made his displeasure clear.
"He's a ripping kid. He said to me, 'I'm not going to be a victim'," Lyon said.
"I don't know - there are plenty of people who maybe choose to be victims, who don't need to be."
He also confirmed Mattaes Phillipou suffered a knock to his leg in training on Wednesday, meaning the Saints young gun must wait longer for a recall.
Phillipou is yet to play this season because of an earlier leg injury.
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