Orient were made to work before booking their place in the second round of the Capital One Cup as they eventually overcame Plymouth Argyle 6-5 on penalties.
The O’s led 2-0 and 3-2 before being pegged back on both occasions to take it down to the wire where O's 'keeper Gary Woods was the hero.
Russell Slade made six changes from the side that lost on the opening day against Chesterfield with Woods, Jobi McAnuff and Jay Simpson all starting their first game for the club.
Scott Cuthbert returned from injury to take a place on the bench whilst Gary Sawyer slotted in at left back against his former employers.
Orient started brightly and it was Simpson who almost broke the deadlock with just three minutes gone when he met a wonderful cross from Lloyd James but volleyed wide.
It was an expansive surface at Home Park and Orient looked to make use of the width and controlled plenty of the early possession but they suffered a blow on 11 minutes when Shaun Batt hobbled off to be replaced by Dean Cox.
The sub soon had his impact when he rifled the O’s in front with a stunning drive from 25 yards after David Mooney did well to win back possession.
It was a fine way to celebrate his 27th birthday and Orient well and truly took control after the goal as Simpson almost doubled the lead when he plundered through on goal but poked his effort tamely at goalkeeper Luke McCormick.
The O’s looked in complete control as they kept possession with ease meaning Woods was a spectator for long periods of the half before they doubled their lead not long before the break.
Cox was the provider this time as he bent in an excellent cross from the right after good work from McAnuff. Meeting his delivery in the middle was an unlikely source in the shape of Mathieu Baudry who gave McCormick no chance with a powerful header.
Orient were cruising but were stunned before the interval when Reuben Reid halved the deficit as he squirmed a shot home after his effort was saved.
It was the first time Woods had been called into any action of note and gave the home side some momentum to end the half.
Orient began the second period in a similar fashion to the way they had controlled the first with Simpson and McAnuff creating half chances in the opening exchanges.
It seemed as if only complacency could topple Slade’s side who knocked it about well but Reid showed a glimpse of quality to wobble them just before the hour mark when he slalomed through the O’s defence before Woods denied him well with his feet.
It was a let off for the O’s but Reid soon had his second when he latched on to a long ball and bundled past O’s skipper Nathan Clarke before rounding Woods to slot home.
Orient were rattled and almost fell behind thanks to a curling strike from Lewis Alessandra that rattled the woodwork with Woods beaten, before the same player came close again with a rasping drive.
Mooney had a chance to seal it late on but was denied by McCormick from close range to take the tie to extra time.
The O’s started the extra period well as Cox was denied with a rasping drive that was well tipped over before his side finally regained their lead.
Cox was again the architect as he dug out a cross that substitute Romain Vincelot met perfectly to glance a header into the far corner.
As the second period got underway Orient were forced onto the back foot and the home side snatched a leveller when a shot by Mellor from distance took a wicked deflection off of McHugh to wrong foot Woods and bounce in.
The O’s were hanging on at the end as Banton rattled the post before Woods pulled off two stunning late saves to take the tie to a shootout.
Russell Slade’s side can take credit for the way they went about their business with the spot kicks, especially in light of the Wembley outcome back in May. Woods was the hero as he saved two brilliantly to give the O’s a 6-5 sudden death win and a spot in the second round.
Finally a special word of thanks to the travelling fans who made the long journey on a Tuesday evening who deserved to see a victory for their side.
PLYMOUTH: McCormick, Mellor, Cox (Allen 106), Nelson (C), Norburn (Harvery 104), Alessandra, Banton, Reid (Morgan 98), McHugh, O'Connor, Hartley
Subs: Bittner, Purrington, Thomas, Smalley
GOALS: Reid 45, 65, McHugh 117
ORIENT: Woods, Omozusi, Sawyer, Baudry, James (Vincelot 86), Mooney, McAnuff, Batt (Cox 11), Clarke (C), Bartley, Simpson (Lisbie 76)
Subs: Legzdins, Cuthbert, Lowry, Pritchard
GOALS: Cox 12, Baudry 38, Vincelot 104
ATTENDANCE: Attendance: 3,343 (141 superb away fans)
Mooney – scored
Lisbie – scored
Sawyer – saved
McAnuff – scored
Clarke – scored
Vincelot – scored
Baudry - scored
Allen – scored
Alessandra – scored
Harvey – scored
Morgan – scored
Banton – saved
Hartley - scored
McHugh - saved