IAIN Hume and David Cotterill fired a thoroughly professional Rovers to their third away win of the season.
Two first half goals in quick succession, including Hume's first for the club, laid the foundations for an empahtic win at Brisbane Road.
Dean Saunders' side did the simple things very well all afternoon, defending in dogged fashion and reducing an Orient side who were unbeaten in their last four games to a limited number of half chances.
Hume broke the deadlock in clinical fashion on 12 minutes.
The Canadian international latched onto Chris Brown's pass, following a clever ball over the top of the defence by David Cotterill, and drilled a fine finish into the bottom corner.
And Rovers doubled their advantage with their second shot on target just nine minutes later.
Kyle Bennett did well to cross from the left and when the ball fell kindly for Dave Syers his goalbound shot was helped on its way by Cotterill.
Orient's threat came mainly from set pieces and long range attempts, while Gary Woods continued his fine form in goal with a faultless display between the sticks.
Skipper Rob Jones, who returned to the starting eleven along with Syers, Hume and Brown, was again outstanding at the back alongside the equally impressive Jamie McCombe, the pair snuffing out what little threat Orient posed.
The only downside to the afternoon was the collection of four yellow cards, including two needless ones for Billy Paynter and Bennett for kicking the ball away.
But Rovers' third away win of the season, which stretched their unbeaten run in League One to four games, was perhaps an indication of the potential of this side.
Doncaster's experience and efficieny came to the fore, and they will now hope to take this sort of form back to the Keepmoat Stadium where wins have been harder to come by.