The Asian side became a stronger proposition after the break and finally secured the breakthrough in the 70th minute when Choe Mi Gyong put Ho Un Byol through for the only goal.
The first half had seemed to suggest that Brazil would be the likely winners in this Group B clash as Alanna set off on a solo run but her shot lacked power. Then Lara dribbled past two defenders but struck the side-netting.
North Korea came much more into the game after half-time, immediately signalling their intent as Choe Mi Gyong got through only to see her attempt blocked at the last moment by determined defending.
In the dying minutes, Choe Kwang Sok's team - six of whom were involved in the recent Asian Cup in which North Korea finished as runners-up to Australia - relied on their strong defence to keep them ahead. They allowed Brazil just one more opportunity - Yun Song Mi almost putting through her own goal following Leah's long throw.
North Korea will play New Zealand at the same venue on Friday while Brazil will look to get their show on the road against Sweden.