Darrell Clarke made one change to the side that were held at home against Colchester United at the weekend as the Saddlers once again came from behind to maintain their unbeaten run.
A second goal of the season for midfielder Rory Holden got the Walsall back on level terms after Danny Johnson had put visitors Leyton Orient in front, before a second half strike from Elijah Adebayo gave Walsall all three points.
It was Orient who went ahead in the game after a third of the first half when Johnson capitalised on a short back pass from Liam Kinsella and he was able to pass the ball into the empty net with Liam Roberts wide of his goal.
Following the setback early in the half, it was all one way traffic from the on for Clarke’s side and they deservedly got their equaliser as Caolan Lavery expertly played a reverse through ball into the path of Holden who calmly slotted the ball past the busy Lawrence Vigouroux.
Eight minutes after the equaliser and the Saddlers had the chance to get themselves the lead as Holden was brought down in the box by Joe Widdowson and the referee instantly gave a penalty kick.
Up stepped Lavery but unfortunately for the striker his low spot kick was well saved by Vigouroux.
Again Walsall piled forward and from a set piece, Holden whipped the ball into the six yard box and a flicked effort by Dan Scarr was once again saved well by Vigouroux.
Into the second half and the Saddlers got their reward for their first half pressure just after the hour mark as the inform Adebayo struck from 10-yards following a blocked McDonald shot.
The ball fell into the path of Adebayo and his superb right footed effort found the far corner, giving Vigouroux absolutely no chance in the Orient goal.
Moments after the Saddlers got themselves ahead, Orient tried their luck and but for a fantastic save from Liam Roberts, Conor Wilkinson would have found himself on the score sheet.
With just shy of 15 minutes left to play it looked as though Holden had bagged himself his second goal of the evening as he picked up a pull back from George Nurse but his curling effort hit the post.