Macauley Bonne’s seventh minute penalty saw Orient go into the break a goal to the good, before Matt Harrold doubled the advantage with a header on the 54th minute.
Bonne then bagged his second of the game nine minutes from time, though Sutton pulled a goal back through Tommy Wright on the 83rd minute. Midfielder James Dayton sealed the victory immediately after however, drilling a deflected strike home from the edge of the box.
Ahead of his first home game in charge of Leyton Orient Head Coach Justin Edinburgh made one change to the side defeated at Solihull, Henry Ochieng was replaced by Alex Lawless.
Sutton got the game underway at the Matchroom Stadium but it was Orient who came out of the blocks the quickest.
Within four minutes of the whistle, the O’s had the ball cleared off the line when Dan Happe attempted to poke Jobi McAnuff’s corner over the line but for Sutton to scramble it away from danger.
Then after six minutes of play, Macauley Bonne smashed home the opener from the penalty spot when James Dayton was pushed to the ground after he worked his way into the box from the wide right.
Moments later, ‘keeper Dean Brill produced an excellent save to deny Ross Lafayette from six yards out.
As Sutton began to enjoy spells of possession, Lafayette’s flick on found Dundas in the box but combined defending from Happe and Brill saw the shot blocked and danger cleared.
Midway through the half, Sutton ‘keeper Jamie Butler dropped a Dayton cross at the feet of Bonne who then tried to chip Butler on the spin but for skipper Jamie Collins to recover and clear off the line.
Again, Bonne went close to a second minutes later after McAnuff beat his man and whipped in a cross from the right which was met by the head of the striker but was directed inches wide of the target.
Orient got the second half going as both teams returned after the break and within ten minutes of the restart Matt Harrold doubled the lead when he headed McAnuff’s free-kick over the rooted Butler.
An excellent challenge on Cadogan from Judd denied the winger the chance to cross from a dangerous position as he raced towards goal.
McAnuff again got the better of his marker and drilled a low cross in to the box which missed Bonney but found Harrold whose shot was blocked six yards from goal.
Dayton’s early cross to the near post was controlled by David Mooney whose attpemt that followed struck the far post but Bonne was on hand to smash the rebound in to the roof of the net to stretch the lead further.
Sutton immediately pulled one back through Tommy Wright who smashed past Brill in the Orient net from close range on the 83rd minute.
The three-goal lead was to be resored within a matter of minutes however, as Dayton drilled home a deflected strike beyond Butler from the edge of the box.
Bonne then left the field to a standing ovation in stoppage time as he was replaced by Josh Koroma for the closing stages, and the full time whistle was met by huge cheers as the O’s celebrated a long-awaited three points.
ORIENT: Brill, Widdowson, Happe, N’Gala, Judd, Clay, Lawless, Dayton, McAnuff ©, Harrold (Mooney 77), Bonne (Koroma (90+3)
SUBS: Grainger, Pollock, Westbrooke
BOOKED: Widdowson (12), Happe (57), (Clay 72), McAnuff (90)
GOALS: Bonne (7 & 81), Harrold (54), Dayton (86)
SUTTON UNITED: Butler, Collins ©, Lafayette, Cadogan (Wright 58), Eastmond (Taylor 64), Bailey, Spence, Walton, Downer, Bolarinwa, Dundas (Stearn 69)
SUBS: Beckwith, John
BOOKED: Walton (6), Collins (41), Downer (84)
GOALS: Wright (83)
REFEREE: Adam Bromley
ATTENDANCE: 4,180 (443)