Two second-half goals in quick succession from Ben Close and Kyle Hurst were enough to hand Doncaster a much-needed boost after Tranmere had earlier hit the woodwork through Ethan Bristow.
Visitors Tranmere created the best chances to score prior to the goal and also went close through captain Kane Hemmings, who was denied by Jonathan Mitchell from close range.
But a slice of luck saw Close break the deadlock when his deflected effort from outside the box flew over Mateusz Hewelt and into the back of the net on 62 minutes.
Three minutes later Kyle Hurst grabbed his seventh goal of the season with a well-taken finish after Charlie Lakin played him through one-on-one.
Brad Walker hit the bar in response for Tranmere but Doncaster held out comfortably to earn just their fifth clean sheet in League Two this term.
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2. Jonathan Mitchell - 8
Pulled off a good save to deny Regan Hendry in the first half before saving well from Kane Hemmings at close range in the second period and pushing a Brad Walker strike onto the bar. Made another good stop from close range in injury time to preserve a much-needed clean sheet. Photo: Howard Roe/AHPIX LTD
3. James Brown - 7
Anonymous in the opening 45 minutes. Looked far more threatening after the break. Photo: Howard Roe/AHPIX LTD
4. James Maxwell - 6
Made several errors in the first period. Recovered after the break, however. Photo: Howard Roe/AHPIX LTD