Heartland stunned holders Rangers 2-0 in their oriental derby clash at the Nnamdi Azikiwe Stadium, Enugu on Sunday.
Suraju Lawal gave the visitors the lead in the 21st minute.
The Naze Millionaires doubled their advantage through Isaac Nassy's three minutes after the break.
The win boosted Heartland's chances of escaping the drop.
Emmanuel Amuneke's side moved to 14th position on the table with 41 points from 33 matches.
The result put a dent on Rangers' chances of securing a top-three finish.
