Jovon Makama's late strike saw City to a big three points in front of a bumper crowd at the LNER Stadium.
The visitors had the first effort at goal in the sixth minute after Tom James’ long throw from the left popped out to Darren Pratley who saw his first-time shot palmed over the crossbar by Lukas Jensen.
City had to be alert in the opening spells to prevent any further Orient chances at goal, with Alex Mitchell rising highest to divert two inviting crosses clear from danger.
Richie Wellens’ side couldn’t make this pressure count despite another flurry of chances midway through the half as Jordan Brown struck wide before Ruel Sotiriou and Shaq Forde’s shots from distance were caught comfortably by Jensen.
City almost caught the O’s off guard with a quick free-kick routine in the 41st minute as Sean Roughan played the ball down the line to Joe Taylor who couldn’t steer his shot on target.
The second period started with both teams fighting it out for a foothold in the game, and thanks to some sturdy defending from the two sides, neither could threaten each other’s boxes.
City and Orient both made changes at the midpoint of the half in the hope of finding a way through, and it almost worked when Hackett’s ball towards the back post was met by Taylor who didn’t find the required contact.
The visitors then had a chance of their own a few minutes later as James’ curling delivery from the right found Ollie O’Neill whose rose highest in the box to head just over the crossbar.
Jensen then had to be alert in the 86th minute as Ethan Galbraith drilled one at goal through the bodies on the edge of the area and forced the Dane to get down quickly and tip the shot past the post.
Jovon Makama made his presence felt after coming off the bench in the 89th minute when he found the ball just inside the box and rifled an effort into the far corner to help see City to a fourth straight win.
Imps: Lukas Jensen, Alex Mitchell, Paudie O’Connor ©, Sean Roughan, Ted Bishop, Jack Moylan (Freddie Draper 64’), Danny Mandroiu (TJ Eyoma 89’), Lasse Sorensen, Reeco Hackett (Dylan Duffy 78’), Joe Taylor (Jovon Makama 89’), Ben House. Subs (not used): Jordan Wright, Adam Jackson, Jack Burroughs.
Goals: Makama (90').
Leyton Orient: Sol Brynn, Tom James, Jordan Brown, Ruel Sotiriou (Ethan Galbraith 86’), Brandon Cooper, Idris El Mizouni (Dan Adu-Adjei 86’), Shaq Forde (Ollie O’Neill 61’), Darren Pratley © (Joe Pigott 78’), Omar Beckles, Max Sanders (George Moncur 61’), Rob Hunt. Subs (not used): Sam Howes, Jayden Sweeney.
Attendance: 9,922 (920 away).
Referee: Carl Brook.