The athlete from Limerick broke Healy's previous record of 11.28 established in the Morton Stadium in 2018 by running the distance in 11.27 in the Galà dei Castelli meet in Bellinzona.
Lavin already broke Derlva O'Rourke's long-standing Irish record for the 100-meter hurdles at the World Athletics Championships in Budapest last month. This is the second new Irish record she has achieved in as many weeks.
On Monday night, Healy congratulated Lavin on social media, writing: “No better and more deserving person to take this record on the back of her national 100m record and the most incredible season both indoor and outdoor.”
After losing her partner, rally driver Craig Breen, in an accident in Croatia in April of this year, Lavin raced at the World Championships in Budapest only a few months later.