Healy spares N.Ireland's blushes vs Azerbaijan
Rauf Aliyev had given the visitors an early lead with a memorable 30-metre curler but Healy threaded a free-kick through the wall in the sixth minute of injury time.
The hosts had earlier missed a spate of chances to pull level, Kyle Lafferty and Craig Cathcart guilty of spurning good openings while Chris Baird twice headed wide with the goal gaping in the second half.
Northern Ireland stayed fourth in the group on three points, one above Azerbaijan on two.
Both sides are well behind group leaders Russia, who have won all four of their matches so far, while Israel and Portugal sit on seven points apiece.