First half strikes from Moses Odubajo and David Mooney secured a comfortable 2-0 win for the O's over Crewe and maintained their 100 per cent start to the season.
Kevin Lisbie missed a first half penalty for Orient but that proved to be immaterial as the O's dominated early proceedings and then soaked up a late onslaught from the visitors to grab another hard-earned victory.
Russell Slade named an unchanged starting XI for the third game in a row while Steve Davis was forced into one change from the side that beat Tranmere last weekend with Max Clayton coming in for the injured Byron Moore.
The O's started the game with the confidence that had seen them chalk up three straight league wins and created the first chance of the match in the third minute when Kevin Lisbie's half volley flew just wide of the target after David Mooney's lay-off.
Crewe didn't heed the warning though and just three minutes later Orient took the lead. Dean Cox found space on the edge of the area before sliding the ball through to Moses Odubajo whose low drive flew underneath Crewe goalkeeper Alan Martin and into the bottom corner from six yards out.
On a sodden Brisbane Road pitch the O's had adapted much more efficiently to the wet conditions than the visitors and Odubajo could have grabbed his second on 14 minutes. Martin failed to hold on to David Mooney's header and the winger was just whiskers away from sliding in the rebound.
The O's had started the game in fine form and could have had a penalty ten minutes later when Lisbie looked to have been bundled over in the area by George Ray. However, as was the case at Stevenage last weekend, the O's penalty cries fell on deaf ears.
But just minutes later the O's penalty misfortune looked to have reversed when Scott Cuthbert was fouled in the area by Chuks Aneke. Referee Keith Stroud pointed straight to the spot but Lisbie failed to convert from 12 yards as his spot-kick flew wide of the target.
The visitors continued to defend their area in clumsy fashion and in the 36th minute Stroud was pointing to the spot again as Mooney was hacked down by Ray in the box. This time it was the Irishman who stepped up and he cooly converted, sending Martin the wrong way to give the O's a richly-deserved 2-0 lead.
It took until the 44th minute for the visitors to create their first chance of any real note as Aneke's curling effort flew harmlessly over Jamie Jones' crossbar from the edge of the area. That would prove to be the final chance of the first half as the O's went into the break two goals to the good after one of the most one-sided opening periods you are likely to see.
Crewe began the second half strongly but once again it was the O's who threatened first when Martin fumbled Mooney's angled drive and Lisbie latched quickly onto the loose ball only to find the side netting from close range.
Just a few moments later Orient came close to grabbing a third in the most comical of circumstances. Anthony Grant played a blind back pass to goalkeeper Martin - who was positioned well away from his goal - leaving the stopper hurtling back towards his posts before clearing off the line at the last minute.
The visitors continued to crank up the pressure and created their best chance of the game on 68 minutes. Scott Cuthbert's weak back pass was seized upon by Ryan Colclough who raced in on goal, however Jones was up for the challenge and saved superbly to deny the forward.
The O's were quickly back amongst the chances though and it was Crewe keeper Martin's turn to deny Mooney from close-range after the forward had been set-up by Kevin Lisbie.
Crewe again came close to bringing themselves back into the game just minutes later as Anthony Grant's long-range piledriver took a huge deflection, leaving Jamie Jones wrong-footed before flying just wide of the target. Jones was forced into action again in the 75th minute, saving well from Ryan Colclough's curling effort.
The visitors were really dominating the late proceedings at Brisbane Road and Jones was once again in top form as he produced a fine one-handed stop to keep Aneke's downward header out. The Arsenal loanee came close again in the 82nd minute as the midfielder found space in the box before seeing his shot rattle the underside of the crossbar.
Orient looked to have soaked up the spell of dominance from the visitors and created another good chance on 86 minutes as Kevin Lisbie's stooping header was well saved by Martin from close-range. That would prove to be the final chance of the afternoon though as Russell Slade's side grabbed another impressive win to maintain their unbeaten start to the season and stay top of League One.
ORIENT TEAM: Jones, Cuthbert, Baudry, Clarke (C), Omozusi, Obubajo (Gorman, 65), James (Bartley, 75), Vincelot, Cox, Mooney (Lasimant, 84), Lisbie
SUBS: Larkins, Sawyer, Lee, Vanderhyde
GOALS: Odubajo (7), Mooney (Pen, 38)
BOOKINGS: James (20), Vincelot (87), Cuthbert (90)
CREWE TEAM: Martin, Tootle, Mellor (Molyneux, 88) , Davis, Clayton, Osman (C) (Turton, 88), Ray, Oliver (Inman, 69), Aneke, Colclough, Grant
SUBS: Phillips, Ellis, Leitch-Smith, Audel
BOOKINGS: Aneke (29), Osman (40), Ray (45)
REFEREE: Keith Stroud
ATTENDANCE: 4455 (332)