Kevin Lisbie struck a late penalty to ensure that the U's finished the season on a high.
The match looked like it was destined to finish as a 0-0 draw, before late drama saw the U's given the chance to win the game.
Lisbie, possibly playing his last ever game for the U's after a season long loan spell, smashed the ball past Jamie Jones to secure yet another home victory and send the U's supporters home happy.
The U's saw David Prutton return to the starting eleven along with Kayode Odejayi. David Fox and Kevin Lisbie dropped to the bench as the U's maintained the formation that had impressed at Huddersfield a week before.
The match got off to a start that did not see too many chances, but the U's were playing well off Odejayi to allow the midfield to join in.
And they were playing with width too, as Vincent and Hackney hugged the wings in an attempt to provide the chance for crosses into the box.
The two wide men almost combined on eleven minutes to send the latter through on goal, but Ashworth intervened in the nick of time to block the ball.
Hackney's runs off the flanks were proving troublesome for the O's back four, but it was almost with his head that he broke the deadlock.
A bursting run from Vincent and swinging cross just eluded the leap of the left winger as he rose at the far post.
Orient had rarely got into the U's box, but the home side were relieved when Thornton's shot from the middle of a crowded area was well blocked and away from danger.
The U's were then within inches of going in front with 22 minutes on the clock. The ball was helped over the O's defence and Odejayi powered past his man.
With Jones rushing off his line to block, the U's man stabbed the ball past the keeper, but agonisingly wide of the far post.
The home side were the ones bossing territory in the opening quarter, but some intricate play around the box by the O's not long afterwards almost found them a path to goal.
White was the man in the right place at the right time, flicking the ball away from danger at the far post. From the resultant set piece, Thornton should have done better with a close range header.
And the O's approached the half hour on top.
The U's withstood a spell of pressure from the visitors before Vincent and Odejayi combined to send the former in through two O's defenders.
They converged on him as he went to take his shot and, under pressure, he pulled his shot well wide of the target.
The winger then turned provider with a clever turn and cross from the right, that Wordsworth couldn't quite extend himself to reach under pressure six yards out.
Thornton hit a shot into the side netting when there were players better placed in the middle of the area, before Wordsworth wasted a free kick by shooting well over the bar.
The midfielder did far better with a header on the stroke of half time, heading Prutton's centre back across goal, with Jones tipping wide with a fine full length save.
The teams went into the half all square but there was a nervous moment at the start of the second half for the home team.
Williams came to the edge of the box to claim the ball but dropped it at the feet of Jarvis. The keeper spread himself enough to just get a toe to the ball from a prone position.
The O's were to have the territorial advantage after the break as the U's lost the possession that they had had the better of in the first half.
To try and freshen it up, the U's introduced Lisbie for Odejayi for the final half hour of the season.
But it was the O's who were to go close next. Jarvis managed to split the two centre halves with his run, but his fierce shot was tipped over the bar with a great save by Williams.
It was followed by a more routine stop by the U's number one, as Lichaj fired a shot straight down his throat from the edge of the box.
Between those two chances, the U's made their second change just after the hour mark, with Hackney replaced by Platt.
The O's were having a number of pacey counter attacks as the U's pressed forwards, and the U's completed their substitutions by introducing Phil Ifil for Vincent on 66 minutes.
The visitors made their first change not long afterwards by introducing Demetriou in place of Smith for the last quarter of the match.
Pressure from Lisbie had Chorley panicking in his area, the central defender eventually thrashing the ball away for a throw in.
The visitors then had a great chance as Jarvis broke away and sent across a dangerous ball that was missed by all bar Chambers at the back post.
His low effort looked like it might be goalbound, but Reid bravely blocked to send the ball away from danger.
Chances like that were rare, however, although Ifil had injected some directness down the right to earn the U's a couple of corners.
It was from a corner th
at he won that he came close to scoring. The ball found him at the far post and his diving header was blocked on the line by Thornton.
McGleish was replaced ten minutes from time to warm applause by both sets of fans, although former Ipswich man Scowcroft wasn't received in the same way by the U's fans as he was introduced.
Williams was sharp on his toes to deny Jarvis as he again looked set to score, before a low cross from&nbsp;Ifil on the right missed both Platt and Lisbie before it was eventually cleared.
The U's were given a late penalty as injury time got underway. The U's had hit the post from the original cross and as Platt followed up,&nbsp;Ashworth&nbsp;blocked on the line with his hands.
The third effort was buried in the back of the net, but the penalty had been given by this point.
Lisbie, making possibly his last appearance for the U's, buried the spot kick beyond the despairing dive of Jones.
And that ensured a winning conclusion to the season as the U's finished on a high.