Scott McGleish scored both goals as Orient gained revenge for their midweek FA Cup exit at the hands of Tranmere with a 2-1 victory.
The Os, seeking their first win in seven games, had the better of the early stages and went ahead in the 24th minute when Andros Townsend and Ryan Jarvis laid on the chance for McGleish to fire into the bottom corner.
Tranmere equalised on the half-hour when home keeper Glenn Morris could only push away John Welsh's shot and Charlie Barnett followed up to score.
Jarvis had a golden chance to restore Orient's lead in first half added time with a one-on-one with Rover's keeper Luke Daniels but fired wide.
But they did go ahead again when McGleish met a cross from Sean Thornton with a near-post header for his seventh goal of the season.
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