Two first half goals from the visitors were cancelled out by goals after the restart from Trialist B and Sam Dalby.
Coach Danny Webb shuffled his side from the midweek FA Youth Cup win over AFC Hornchurch.
Teddy Perkins and Alfie Fleming were rested whilst Ruel Sotiriou was on first team duty, meaning the trio were replaced by Trialist A, Luca Carter-Henry and Brendon Shabani respectively.
There was little between the sides early in the game but Orient missed the chance to go ahead when Ernold Haxhiu’s wide ball was collected by Eric Lopes who then drilled a first time cross towards Sam Dalby who was just beaten to the ball by the defender who cleared the danger.
Soon after, Hector Kyprianou fired a shot over the target from close range after some good work out wide by Luca Carter-Henry who managed to find the midfielder inside a congested box.
But it was the Daggers who opened the scores when Jack Lee rose highest to head home from a free-kick wide left of the goal.
Almost immediately, Charles Clayden latched on to the edge of a Haxhiu pass but was quickly closed down by the ‘keeper who rushed out to block the wingers shot.
The O’s went close again through Sam Dalby whose 20-yard free-kick struck the post before being cleared of danger by a Dagenham & Redbridge defender.
Against the run of play, the visitors stretched their lead through Lanre Balogun who tapped in a low cross from the left to put his side two goals ahead.
Within two minutes of the restart, Orient clinched a goal back through Trialist B who towered above everybody else inside the box to head home.
Dalby notched the equaliser for his side moments later with a neat finish from close range to stun the visitors who thought they had a comfortable lead at the break.
Orient could have completed the perfect come-back and grabbed a third when Clayden’s drilled cross was missed by Dalby and landed at Carter-Henry’s feet unexpectedly, but the midfielder didn’t have time to adjust his position and the danger for the Daggers was cleared.
As full time approached, Arthur Janata pulled off an excellent diving save to keep the O’s level and neither side could quite grasp a winner as the points were shared.
ORIENT: Arthur Janata, Andrew Camilo-Tayaca, Toby Stevenson (C), Trialist A (Trialist B HT), Brendon Shabani, Hector Kyprianou, Ernold Haxhiu (Teddy Perkins 53), Luca Carter-Henry, Eric Lopes, Charles Clayden, Sam Dalby
SUBS: Samuel Amedu, Jaedon Phillips, Alfie Fleming
GOALS: Trialist B, Dalby