They tackled an armed woman to the ground, but the five Perth teachers did not forget their manners - they offered the intruder a cushion for her head until police arrived.
The five women, who work at St Stephens School in Duncraig, have been honoured for their heroics in the annual Australian Bravery Awards after being confronted in February last year by a woman carrying a 27cm chopping knife.
The intruder seized a child by the arm at the school's early learning centre, but released the student when challenged by Year 1 teacher Katherine Hilder.
Ms Hilder grabbed the intruder and subtly forced her out of the classroom, leaving the children unaware of the unfolding drama.
She began to struggle, but by then, fellow teacher Heather Louise King had heard her colleague's call for help and grabbed the arm of the intruder that was brandishing the knife.
Both teachers continued to push the intruder away from the students and were joined by two more colleagues - Sally McAlpine and Jo-Anne Urquhart.
Ms Urquhart managed to snatch the knife away.
"Kate yelled, `quick, get the knife' so I just grabbed the woman's hand to pull the knife out," Ms Urquhart told AAP.
She said the teachers realised the woman was not mentally stable, so they offered her a cushion while keeping her pinned down.
Ms Urquhart then left her colleagues to commence a lockdown, and ensured all students were safe until police arrived.
"The kids thought it was a drill, but then it went on for too long so we explained that there was a sick woman who needed help," she said.
"None of the children even realised what had happened."
Ms Hilder, Ms King, Ms McAlpine and Ms Urquhart were each recognised with bravery medals.
Fellow teacher, Rosalie Michelle Brades, was also commended for her brave conduct in maintaining hold of the intruder.
Ms Urquhart said she and her fellow teachers were surprised to receive the award.
"It is lovely to be recognised. I'm humbled," she said.
"It is great to be able to rely on everyone you work with."
The four bravery medals were among 21 approved by Governor General Quentin Bryce this year, along with 31 commendations for brave conduct and 10 group bravery citations.
Ms Bryce said the recipients had placed the safety and lives of others before their own.
"We are privileged to have such role models in our society," she said.