Francisca Ordega's super strike on the stroke of halftime was cancelled by Giovanna Oliveira with three minutes of time left as Brazil clawed their way back into contention.
The point kept the Super Falcons top of the group with Italy yet to face Korea in the group's other game, but Nigeria will see it as two points dropped rather than a point gained.
Brazil started the game with more composure, as the Falconets looked to press with a high-risk, early intensity.
But it was the Brazilians who continually unnerved the Nigerian back line with their incisive movement and passing.
They almost went in front when Ibubeleye Whyte Only to a fingertip to what should have been a routine low cross.
Fortunately, skipper Gloria Ofoegbu was on hand to mop up the spill with Ketln lurking at the back post.
With three minutes to the break, the Falconets turned it up. From nowhere, Ngozi Okobi laid a nothing ball to foot for Ordega. The former Under-17 striker spun and let rip into the low left hand corner from 20 yards.
Spurred by the goal, the Nigerian ladies carved out two more chances. First Okobi flashed one wide from distance, and then Desire Oparanozie only just missed with a lob over goalkeeper Danielle, who was hopelessly out of position.
But Brazil survived and Nigeria were made to rue those misses.
Gassing out from all that early running, the Falconets were pinned to their half. And things took a grim turn when first choice goalkeeper Ibubeleye Whyte appeared to twist her ankle, forcing a substitution.
With the pressure piling, Edwin Okon threw on first Ebere Orji, then Blessing Edoho.
If Orji helped ease the pressure upfront, Edoho exacerbated it. Her first contribution was to give away a free kick, and pick up a yellow card with a badly mistimed challenge.
Captain Thais Guedes floated in the perfect ball, and Oliveira stole in to glance her header past substitute keeper Chioma Nwankwo.
A buoyed Brazil tried to go for the kill, but Nigeria held out in the end to leave the group finely balanced.
If Italy beat Korea in the second game, they would be level on 4 points with Nigeria.
And if both Nigeria and Italy draw in their final game on Sunday, and Brazil beat Korea, all three teams would finish on 5 points.
Goal difference would then kick in as the first tie-breaker and not head to head.