In an enthralling encounter in North Lanarkshire, the Ainslie Park side were just seconds away from taking all three points until Corey Wellings struck in the third minute of additional time to salvage a point for the Glasgow outfit.
Having fallen behind to Tegan Bowie's 11th minute strike, a brace from Spartans' Rosie McQuillan had Debbi McCulloch's side going in at half-time with the lead.
The hosts upped the tempo in search of an equaliser but the Capital side's defence stood firm until Wellings had the final say.
Boss McCulloch said afterwards: "It was a fantastic, gutsy performance from the players. I'm so proud of everyone on and off the pitch. We showed the quality, courage and determination we have within our team."
Despite picking up a well-deserved point, Spartans slip one place to eighth in the SWPL 1 standings.
Elsewhere, Hibernian Women returned to winning ways as Colette Cavanagh's first-half strike was enough to sink Aberdeen at Livingston's Tony Macaroni Arena.
The result extends the fourth-placed Hibees' lead over the Dons to five points. Midfielder Shannon McGregor, who was making her 50th appearance for the club, made a welcome return to first-team action after suffering an ACL injury last year.
And Hearts suffered a disappointing 2-0 defeat to Motherwell at Alliance Park, a loss that sees the Jambos slip to the foot of the division.