Orient went ahead through Romain Vincelot's well-taken header, only for the Rs to level thanks to a low long-range effort from Junior Hoilett.
Joey Barton put Harry Redknapp's side in front with a well-taken free-kick in the second half, but the Os equalised with just six minutes to go when Dean Cox found the bottom corner from the edge of the area.
Burnley conceded a late winner to go down 2-1 against Preston in front of former North End and Manchester United manager David Moyes, who was in the crowd at Deepdale
The opening goal came in the 15th minute when new signing Lukas Jutkiewicz dispossessed Bailey Wright to put Burnley in front.
Preston's equaliser came seven minutes after the break as Alan Browne found the net, and their winner came in the final minute thanks to Josh Brownhill's superb free-kick.
Bafetimbi Gomis scored his first goal for Swansea and Josh Sheehan was also on target as Garry Monk's men secured a 2-0 victory over Exeter at St James Park.
Gomis, who also hit the post later in the game, opened the scoring when he got his head to the end of Neil Taylor's cross.
Stoke City's tour of Germany ended with a 2-1 defeat at the hands of Schalke, with new signing Bojan opening his account for Mark Hughes' side following his move from Barcelona.
Bojan found the net in the 55th minute but Schalke levelled soon after through Joel Matip before Tranquillo Barnetta then scored the winner five minutes from time.
Mikael Mandron scored the only goal of the game from the penalty spot as Sunderland enjoyed a 1-0 victory over Recreativo de Huelva in Portugal.