Kwesi Appiah missed from the penalty spot as Conference Premier leaders Cambridge were held to a goalless draw at Chester.
Luke Berry went close for the U's before Appiah forced a decent save from Chester keeper John Danby.
Appiah then fired his spot-kick wide just before half-time after Harrison Dunk was brought down in the box by George Horan.
Nathan Arnold and Adam Cunnington went close after the break.
Cambridge, who are six points clear of second-placed Kidderminster, are now unbeaten in their last 15 games.
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Chester manager Neil Young told BBC Radio Merseyside:
"A point is probably a fair result on the day.
"We want to win games at home but you've got to realise what you're up against and they're as well-organised as I've seen in this division.
"It's another good point for the boys. There was no quarter given and they battled hard."
Cambridge United boss Richard Money told BBC Radio Cambridgeshire:
"If I said to them on the bus before we went to Grimsby, we would have four points and two clean sheets this week, they'd have snapped my hand off. It was another good effort from the team.
"We haven't been able to make the breakthrough, but I thought we played well enough to do it. Profligate is our famous word at the moment. We'd like to score more from the chances we're creating but it's another good performance and another good point.
"I think it's very important that people realise that we defend as a team and we attack as a team. The team has won another clean sheet not just the back four and the goalkeeper."
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