Russell Slade's side earned a 1-1 draw at home to struggling Sheffield United as Kenny Jackett's charges slumped to a 1-0 loss at London Road.
Orient had to come from behind to earn their point, Dean Cox's goal eight minutes from time cancelling out Conor Coady's strike 15 minutes earlier.
Michael Bostwick's goal ended Peterborough's run of five consecutive defeats, while for Wolves it was their first defeat in 12 matches.
Preston North End are six points adrift of the leading pair in third after a 1-0 home win over managerless Bristol City, Jack King claiming the only goal in the 33rd minute before the both sides were reduced to 10 men in the final minute.
Level with Preston are Brentford, who were indebted to Will Grigg's 44th-minute goal as they sealed a 1-0 win at bottom club Notts County, who are now without a win in five matches.
Sixth-placed Rotherham United extended their unbeaten run to five games with a 4-1 thumping of Gillingham as Nouha Dicko, Kieran Agard, Ben Pringle and James Tavernier all found the net.
Swindon Town are a point shy of the top six following a 3-1 home win over Carlisle United.
Massimo Luongo put the hosts in front nine minutes before half-time, only to see Sean O'Hanlon level matters in the 69th minute.
Parity lasted just three minutes as Alex Pritchard struck, before Dany N'Guessan's 90th-minute strike earned Swindon their first win in three.
At the wrong end of the table, Crewe Alexandra lifted themselves to within a point of safety with a 1-0 win over managerless Crawley Town.
Crewe had Vadaine Oliver sent off for a second caution 10 minutes after the break, but they were able to find a winner as Chuks Aneke came off the bench to strike with nine minutes remaining.
Stevenage dropped into the bottom four after going down 3-1 at home to Shrewsbury Town, who climbed to 13th while elsewhere, there were wins for Tranmere Rovers, Coventry City and Port Vale.
