Whilst the U's weren't at their fluent best, they still played well enough in spells to test the Rovers defence.
But, when they did get through, they found Thorsten Stuckmann in the way, with the big German pulling off three or four fine saves.
The best of the lot came with the U's two behind, clawing away a Darren Ambrose header.
So, three defeats in a row on the road for the U's, but they remain in fifteenth place in the League One table.
The U's made one change to their starting eleven, with Frankie Kent being replaced by the returning Matt Briggs at left back.
Unlike the frantic pace of the game the week before, the match at the Keepmoat Stadium took a little while to fire into life.
The home side were the first to get a sight of goal, as Tyson got in behind Eastman, but Jones stood strong to block the front man's effort and see it away to safety.
At the other end, Garvan's free kick clipped the wall for a U's corner, and the set piece caused danger before it was eventually cleared.
The U's went close again on eleven minutes when Moncur seized the initiative and curled in a left footed shot that forced a good save out of Stuckmann.
Moncur beat the keeper on the quarter hour mark, but was denied by the woodwork as his fierce shot from an angle cannoned back off the woodwork.
Midway through the half, it was Harriott's turn to take a shot that was at a good height for Stuckmann to turn away acrobatically to keep it scoreless.
The home side were enjoying some possession, but it was the U's who were the more incisive as the half hour approached.
Harriott sent across a fine ball from left to right and Ambrose flashed a volley right across the face as the U's again threatened.
The chances dried up a little, with Jones showing some safe hands to sweep up and Rovers pressure.
At the other end, Sordell did well to lay it off to Gilbey, but he flashed his shot wide of Stuckmann’s near post from distance.
The U's had defended well in the first half, but found themselves a goal behind four minutes before the interval.
Debutant Conor Grant picked up the ball and bent the ball into the top corner, giving Jones no chance as the U's fell behind.
The home side led at the break and started the second half with their tails up, but the U's had chances of their own to level.
Harriott stung the palms of Stuckmann who punched away, before at the other end Coppinger was denied a clear shot at goal as Olufemi got back in.
The U's had their heads in their hands on 62 minutes when Butler screwed a Harriott cross over the bar, as it dipped just past the woodwork.
Then, at the other end, Coppinger got away and unselfishly squared for Williams to slot home and double the home side's advantage.
The U's almost conjured an immediate riposte as Harriott stood up a cross to the far post that Ambrose arched his back to power towards goal, but Stuckmann pulled off a quite brilliant save.
It was a fine stop and Ambrose appeared to take a blow to the head in trying to score, and was swiftly replaced by Bonne.
Main almost made it three to the home side after showing some twinkle toes in the box, but his effort went past the far post.
The U's kept probing, with Harriott proving dangerous down the left, but they couldn't find a way to test Stuckmann again.
There were four additional minutes added on at the end of the match, and Briggs had two shots blocked in quick succession in the final moments.
But, as had been the case through the afternoon, they couldn't find a path to goal and they fell to a 2-0 defeat.