Goals from George Porter and Jack Holland put the hosts ahead at the break, before Josh Rees and Adam Mekki notched after the break.
Forward Macauley Bonne pulled one back on the 66th minute, but Bromley added a fifth on the 74th minute as Holland notched his second before Brett Williams completed the scoring two minutes from time.
Having recorded six points from our opening three fixtures, Head Coach Steve Davis made two changes for the trip to Hayes Lane as Josh Koroma and Romuald Boco came in for Jobi McAnuff and James Dayton who both dropped to the bench.
With a strong Orient following in attendance, the O’s got off to an encouraging start as forward David Mooney first saw a shot from distance held by former loanee David Gregory, before having a shot deflected wide of the post.
Despite the promising opening few minutes, it was Bromley who made the breakthrough on the 11th minute through a former O when George Porter glanced a header beyond Charlie Grainger and into the back of the net.
Having fallen behind, Grainger brilliantly denied the hosts a second goal six minutes later when the O’s number one pulled off a great stop to thwart Louis Dennis after the Bromley forward had pounced on a defensive error from George Elokobi.
Captain Charlie Lee then saw a shot deflected wide of the post as we pushed for an equaliser, and moments later Elokobi looked to have levelled the tie with a powerful header from Romuald Boco’s corner only for Gregory to parry away the effort.
Unable to force an equaliser, the O’s were dealt another blow six minutes before the break as Bromley captain Jack Holland emphatically headed home from Frankie Sutherland’s corner to double their lead.
As the half drew to a close, Josh Koroma and Macauley Bonne saw efforts blocked either side of Luke Wanadio being denied by Grainger as Bromley went into the break with a two-goal advantage.
Looking for a strong reaction from his side in the second half, Head Coach Steve Davis made a double substitution as Jobi McAnuff and James Dayton replaced Boco and Koroma.
The substitutions proved to have an immediate impact for the O’s as McAnuff saw a free-kick blocked before clipping a cross back into the box which found Josh Coulson whose header was brilliantly tipped over by Gregory.
Dayton was then in the thick of the action soon after as he played a brilliant one-two with Bonne before drilling a low shot towards the bottom corner which was parried away by Gregory.
Despite the pressure it was the hosts who grabbed the third goal of the night, when midfielder Josh Rees poked home from close range after Wanadio’s effort was parried up in the air by Grainger and Jake Caprice failed to clear the danger in time.
It was 4-0 just after the hour when Louis Dennis drove forward and saw thumping drive parried away by Grainger, but only into the path of Adam Mekki who was left with a simple finish into an empty net.
A strong response was certainly needed, and with just under 25 minutes remaining the O’s pulled a goal back when Mooney expertly picked out Bonne in the area with a chested pass before the forward kept his composure to register his first goal for the Club.
Bromley were able to add a fifth however on the 74th minute, when captain Holland bagged his second of the night after Orient failed to clear a corner into the box.
With five minutes remaining Lee looked to have pulled another goal back with a header from close range, only to be denied by Gregory who wonderfully tipped his effort over the bar.
As the full time whistle approached Bromley added a sixth as substitute Brett Williams benefitted from a loose pass from Lee to round Grainger and fire home to round off a disappointing evening for the O’s.
BROMLEY: Gregory, Wynter, Chorley (Johnson 76), Holland (C), Sterling, Wanadio, Sutherland, Rees (Raymond 82), Mekki, Porter (Williams 72), Dennis
SUBS: Dunne, Allen
GOALS: Porter (11), Holland (39 & 74), Rees (55), Mekki (62), Williams (88)
BOOKED: Chorley (48), Rees (71)
ORIENT: Grainger, Caprice, Coulson, Elokobi, Widdowson, Lawless, Lee (C), Koroma (Dayton HT), Boco (McAnuff HT), Mooney, Bonne
SUBS: Sargeant, Clark, Clay
GOALS: Bonne (66)
BOOKED: Caprice (59), Lawless (77)
REFEREE: Samuel Allison
ATTENDANCE: 3,346 (1,037 Orient supporters)