A late strike from Andy Pugh helped Cambridge move above Barrow with a hard-fought win at the Abbey Stadium.
The visitors had nearly taken the lead when Andy Cook's shot from outside the box struck the post.
And they again came close when Paul Smith's right-footed effort was saved by Danny Naisbitt.
But it was the home side who struck late, Pugh converting inside the box from John Dawkin's cross to inflict a third consecutive defeat on Barrow.
VIEWS FROM THE TRAINING GROUND
Cambridge United boss Jez George told BBC Radio Cambridgeshire:
"I've said to the players that's the most pleasing way we've won all season in many respects.
"It's big pressure for lads when they play at home and want to please everybody when they know we've lost our last three at home in the league.
"We also know performance levels weren't so good as they were earlier in the season.
"We really had to dig tonight to in but I thought we showed some maturity."
Barrow boss Dave Bayliss tells BBC Radio Cumbria:
"We've dominated the game from start to finish and had some unbelievably good chances.
"When you don't take them you leave yourself open to one scruffy type of goal.
"They've got that towards the end, the lads have given everything tonight.
"We've done everything in the game apart from score but that's what wins you games."