An Iain Vigurs strike right at the death grabbed a point for Ross County and denied Hearts victory.
Rocco Quinn's deflected shot opened the scoring for the home side after 20 minutes but Michael Ngoo equalised.
Jamie Walker headed Hearts ahead but Vigurs' equaliser came in the second minute of stoppage time.
Both keepers made vital saves in a game where victory by two or more goals would have lifted Hearts into the Scottish Premier League's top six.
Instead, John McGlynn's side move up to eighth, while Derek Adams' County remain 10th but are now 15 points clear of bottom club Dundee.
Hearts had a number of early chances, beginning with a move which involved Danny Wilson and Billy King before Jason Holt shot wide.
Ryan Stevenson was next to come close for Hearts and King then pulled one of the game's several great saves out of Mark Brown.
County won a series of corners and their fourth one led to the opening goal. Vigurs found Quinn and his 15-yard shot eluded Jamie MacDonald after a hefty deflection.
Stevenson fired wide after a through ball from Marius Zaliukas but then supplied Ngoo for the leveller, the striker cruising past central defenders Grant Munro and Scott Boyd to beat Brown.
Next it was MacDonald's turn to star with a great save from Quinn.
The second half was a good deal less entertaining than the first until 62 minutes when Fraser Mullen's cross found Walker six yards out to put Hearts in front.
The keepers were then back in business when Brown pushed Stevenson's effort round for a corner before MacDonald saved from Paul Lawson and then Brown got a hand to an Andy Webster effort.
By now County were throwing everything they had at Hearts and it paid off in stoppage time when the ball seemed to spend an eternity in the Hearts box before presenting itself to Vigurs for a tap-in to finish.