Goals from Michael Gash and Tom Shaw helped in-form Cambridge to victory over Darlington.
The U's gained the lead when Gash slotted home from six yards out after Ashley Carew's delivery.
Visiting boss Mark Cooper was sent to the stands at half-time, and his frustration continued when he saw Greg Taylor's effort ruled out for offside.
Cambridge secured the win when Shaw fired in his second league goal of the season from just inside the area.
VIEWS FROM THE DRESSING ROOM
Cambridge United boss Jez George told BBC Radio Cambridgeshire:
"It's been a brilliant week as we've taken seven points from three tough matches.
"Today's win makes it back-to-back victories for the first time since I took over here.
"It's another clean sheet and a good display as well."
Darlington boss Mark Cooper tells BBC Tees:
"I'm more disappointed than frustrated, again our so called bigger players didn't play to their reputations, and for me things have got to change.
"The way I see it is there will be a few leaving, and a few coming in, that's 11 games gone and we've only won three, so something has to give.
"There was nothing in the game when they scored, it was an 80-yard cross-field ball, the left-back is not tight, he let him cross it, and free shot in the six yard box. That's not a team that is disciplined and organised."