Louis Laing was the most unlikely of heroes for ten-man Hartlepool United as three points at Victoria Park ensured their National League safety for another year.
Laing popped up with a 39th minute winner to make amends for two high profile errors in his last two games.
While fourth-bottom Barrow can still catch Pools due to games in hand, Woking and the three below the Cumbrians cannot.
And as a result, with three games remaining Pools finally have on-field safety to go with stability off it.
On the selection front, Matthew Bates went with the same side who battled to a 1-1 draw at Sutton United at the weekend - resisting the temptation to throw Rhys Oates back in, with Ryan Donaldson starting just his second game from October.
Having talked about anxiety on the terraces at Victoria Park and the need to calm it with performances on it, Bates' men did little brighten the mood with a nervy show.
They could and should have been behind less than 20 minutes into the encounter as the O's carved Pools' backline open at will.
Josh Koroma was presented with a gilt-edged opportunity to open the scoring, but having been set free of a static backline he fired wide with the goal at his mercy.
It was a let off of the highest order for Pools and one which they failed to react to, as Orient kept their peddle to the metal, with the home side pinned back as boos reigned down from the Vic faithful.
Despite a dismal opening half hour, Pools began to offer a little more purpose in the final third as the game wore on. Jake Cassidy should have done better when set loose with a delightfully weighted ball by Josh Hawkes, then, almost out of the blue, they were in front.
A floated free-kick from the left was nodded in at the back stick by last week's villain Laing. Cue wild celebrations both on and off the park.
Much like the pattern of the opening 45, the hosts let their opponents do much of the early running and they came close to levelling on two occasions within a minute.
Shortly before the hour Samuel Ling rose highest in a crowded area to nod goalwards but his header was scrambled clear off the line, and in the melee that followed substitute Daniel Happe cracked off Scott Loach's bar as Pools weathered another Orient storm.
Striker Macauley Bonne was next to go close with a six yard header before Lewis Hawkins cleared a Marvin Ekpiteta effort off the line as the clocked ticked over to 90.
In the four minutes of added time, substitute Devante Rodney was shown a red card after commiting two silly fouls, but it mattered little as Pools saw the game out on home turf, having failed to do so on their last two attempts.