Sheffield United boss Micky Adams was left wondering what might have been following the 3-1 defeat at Preston which leaves his side eight points adrift at the foot of the npower Championship.
Bjorn Helge Riise slammed a 49th-minute sitter against the crossbar from close range before a Keith Treacy brace put North End in control of the game.
Jordan Slew pulled a goal back for the Blades but Nathan Ellington wrapped up the points with a goal on the counter in the 90th minute.
Adams said: "It sums our season up in many respects that we've created enough chances in games of football to have won them, drawn them, got something out of them.
"The defining moment was Bjorn's miss - most people in the stadium would have put that in.
"Since I've been at the club, I've said all along I can't really fault the players' efforts or enthusiasm, but we're just not helping ourselves."