The hosts took the lead in less than two minutes. A ball was crossed to the number 7, who wiggled himself into a yard of space, before firing the ball across Rhys Byrne and into the back of the net.
Orient rarely found a way forward, but Jayden Sweeney’s whipped ball into the box was almost met by Jaedon Phillips, however the striker was unable to get on the end of it.
At the other end, Rhys Byrne did exceptionally well to claw away a bending effort that would have crept inside his near post. The Keeper got his finger tips to it and forced it out for a corner.
The Seasiders doubled their lead from a set piece. A whipped ball in from the left-flank, was helped on by the head of a man in navy, and into the bottom corner to put the hosts 2-0 up.
A short corner was then looped towards the far post, where a Southend man had a free header, and found the net, to make it 3-0 before 25 minutes.
Phillips tried his luck from distance, as Southend limited Orient’s chances to shots from distance frustration began to creep in.
Byrne was forced into action again, the Keeper who had just returned from injury, got down well to save the ball to his left to block an effort from close range, and then smoother the loose ball.
The Hosts continued to dominate the half, adding a fourth goal before the half-time whistle, as they were in control of the game.
Orient started the second half a lot more controlled, but still couldn’t find goal scoring opportunities. Phillips tried his luck from 40 yards, after spotting the goalkeeper of his line, but the striker’s effort whistled over the bar.
O’s midfielder Ahmed Mirza rifled an effort above the target, after the ball fell kindly to him on the edge of the box, 67 minutes in.
Southend found their fifth goal 20 minutes from time. A Shrimpers substitute played a smart one-two with a teammate, before stroking the ball home from ten yards.
The final goal of the game came after 73 minutes. United won the ball on the half way line and broke at speed. A pass across the edge of the box assisted the striker, who took one touch, and then buried the ball into the bottom right-corner.
Orient failed to find a consolation in the closing moments, as Southend proved to be the better team on Saturday morning.
Next, The O’s travel to Luton as they play their second consecutive away tie. The two teams have already clashed this season, with The Hatters coming from behind to win the game 2-1. Jaedon Phillips had opened the scoring after 15 minutes, after tapping in Charles Clayden’s whipped cross.
ORIENT: Rhys Byrne, Jeremie Sivi, Jaydon Sweeney (Diego Bonne 75), Ahmed Mirza, Mason Hall, Wynford Marfo, Lawrence Hammond (Anthony Papadopoulous 47), Bradley McClenaghan, Jaedon Phillips, Callum Nevson (Jayden Yang 60), Charles Clayden
BOOKED: Marfo (35)