Kevin Ellison’s quickfire second-half double made it seven points in a week for the Shrimps and extended their unbeaten run to six games.
The veteran struck twice within five minutes at the start of the second half as Jim Bentley’s side proved full value for their victory.
Just as the fans did their bit by providing only the fourth crowd of the season in excess of 2,000, so did the players with a victory that could have been greater but for the efforts of Cambridge keeper Will Norris.
He made fine saves to deny Paul Mullin, Lee Molyneux and Aaron Wildig, while the post thwarted the impressive Mullin’s hopes of another goal.
Bentley had made one change to the side which won at Leyton Orient in midweek.
Alex Kenyon was restored to the back three as illness ruled out Dean Winnard and accounted for Andy Fleming’s absence from the Shrimps’ matchday squad.
An entertaining first half saw both sides committed to attacking but it was the home side who had the better of the opportunities.
Shrimps’ skipper Peter Murphy converted Michael Rose’s early corner but his celebrations were cut short by a booking as referee Nigel Miller ruled he had handled the ball.
Mullin almost opened the scoring on 16 minutes but, having collected Rose’s through ball, saw his shot cannon back off Norris’ right-hand post.
The woodwork also denied the visitors when Jake Carroll turned a cross goalwards, only for his effort to trickle off the post and Shrimps’ keeper Barry Roche to grab the loose ball.
Norris made an excellent low stop to keep out another Mullin shot as the half ended goalless - though that was to change quickly after the break.
Cambridge substitute Harrison Dunk had headed over on 47 minutes, three minutes before Ellison grabbed centre stage.
Norris kept out Michael Duckworth’s header but Ellison was first to the loose ball and converted despite the keeper’s best efforts.
Molyneux was denied by Norris moments later but Ellison doubled his tally on 55 minutes, slotting home after Mullin’s effort was parried away.
United’s response was to introduce Barry Corr and Ben Williamson off the bench but it was Bentley’s players who were still the likelier to score.
Norris was called into action again, keeping out Wildig’s low effort before pushing another Molyneux shot into the air and away.
In contrast, Roche was relatively untroubled at the other end as the Shrimps comfortably held out for three more points.
Morecambe: Roche, Edwards, Whitmore, Kenyon, Duckworth, Murphy, Wildig (Evans 87), Rose, Molyneux, Mullin (Turner 76), Ellison (Jordan 90). Subs not used: Nizic, Wakefield, McGowan, Conlan.
Cambridge United: Norris, Legge, Roberts, Wharton (Dunk 46), Mingoia, O’Neil, Dunne, Newton (Williamson 58), Carroll, Berry, Ikpeazu (Corr 58). Subs not used: Gregory, Maris, Clark, Lewis.
Referee: Nigel Miller.