The heady days of early January when Yeovil met Liverpool in the FA Cup were fast becoming a distant memory as the Glovers slipped to their fifth defeat in six outings.
Yeovil introduced new boy Simon Weatherstone from Boston United and he had a moderate debut which included setting up a consolation goal late in the game.
Yeovil, in fact, managed 14 shots against just three by the visitors. But it was Orient who made their finishing count.
In the 25th minute Mark Peters got up superbly to head in a free kick from Dave Hunt - his first goal since his arrival from Rushden and Diamonds in September.
Three minutes later a long throw by Hunt found its way through the Yeovil defence and Gary Alexander was at the far post to smash a first-time shot past goalkeeper Chris Weale, who has been training with West Ham this week.
Orient, who had lost four consecutive away matches were now on their way.
"It wasn't our best performance of the season - that was at Cambridge. But it was certainly a hard working one and it had to be at Yeovil," said manager Martin Ling.
Ling told his players not to sit back in the second half - and was annoyed that they did. They allowed Yeovil to press them incessantly but it was not until the 76th minute that Yeovil scored their goal.
New boy Weatherstone provided the cross and substitute Nick Crittenden swept it in at the far post.
Yeovil might have saved the game in the 89th minute when top scorer Kevin Gall got clear but his final shot hit a post and was scrambled clear.
Referee Mark Warren had to be replaced on 72 minutes after pulling a muscle, leaving fourth official Mike Mullarkey to finish the game.