Millwall are on course to guarantee their Championship safety thanks to Karleigh Osborne's first-half goal against Blackburn Rovers.
Osborne broke the deadlock in the 14th minute by lashing a loose ball into the net after Scott Dann had failed to clear a free kick.
The hosts almost doubled their advantage when James Henry took on a 30-yard free kick, but it was tipped over by Grzegorz Sandomierski.
Three points for the Lions tonight would see them rise to 13th in the table.