Oxford and Bristol City played out a messy goalless draw at the Kassam Stadium in Matt Bloomfield's first match as Oxford's new boss.
The point leaves the Us second from bottom in the Sky Bet Championship table.
After a scrappy first half lacking in quality, Oxford had some attacking moments near the end but City defended resolutely and goalkeeper Radek Vitek had only two saves of note to make.
The most important one came in stoppage time when he superbly saved Stan Mills's shot with his foot.
The Us gave a debut to 20-year-old Turkish midfielder Yunus Konak, who has signed on loan from Brentford until the end of the season, while the Robins welcomed back Vitek after a knee injury.
Spectators had to wait until the 14th minute for the game's first effort on goal, City's Scott Twine firing in a low shot from distance that brought a comfortable save from Jamie Cumming.
After good work on the right by Zak Vyner, striker Emil Riis might have done better than shoot wide from 14 yards in the visitors' next attack.
For a spell the play was very scrappy with referee Tim Robinson constantly blowing up for fouls, and United found it hard to develop any rhythm to their play.
When Bristol City were awarded a free-kick in a very dangerous position, central and 20 yards out, Twine must have fancied his chances - but he bent his shot over the bar.
Bloomfield brought on Will Vaulks for Konak for the second half, while George Earthy replaced Twine for City.
Riis headed over from a difficult chance early in the second half as the game started to open up more, though Oxford were still struggling to get close to Vitek's goal.
Cameron Brannagan continued to try to make things happen for the home side, but kept running into cul-de-sacs as City closed down space well.
When Will Lankshear turned a right-wing cross from Sam Long narrowly wide, it lifted the home fans, although Lankshear was offside in any case.
It also renewed belief in Oxford's players and in the 73rd minute they managed their first effort on target, with Vitek saving from Mills and Brannagan seeing his follow-up effort blocked.
Bloomfield's men were at last looking more threatening, especially when Mills was released down the right.
Substitute Yu Hirakawa added some energy for the Robins and was a danger down the left, but the match petered out.
City at least prevented Oxford doing the double over them, after they triumphed 3-1 at Ashton Gate in September, but this was a game that will not live long in the memory.
Oxford's Matt Bloomfield:
"I thought we were excellent. In the second half we created multiple opportunities, we had the momentum, it just felt like a matter of time before we got that goal.
"Stanley Mills had one saved, we had one cleared off the line - we came close so many times.
"Unfortunately for us, it wasn't to be but in terms of performance, endeavour and that all-in togetherness with our supporters and the atmosphere they created when we were attacking that end, there were a lot of good bits for me.
"It was our first clean sheet in a long time, so we have to retain that and get more clean sheets to get the wins we need.
"Bristol City are a team that have been in good form, a fine Championship team, scoring goals for fun in recent games and we've limited them to very little.
"There wasn't much happening first half. I took off Yunus Konak to protect him because he was on a yellow card. It was hard for him because he'd been in the building only two days and was thrown into his first Championship start but Yunus did fine - he's a young player of huge potential.
"The training we've done this week has been really good and the welcome I've received from all the players, the staff and the supporters has been great.
"The only way you win football matches is if you're all in it together. If we can keep putting that kind of performance out, I have full belief in what we're going to do."
Bristol City's Gerhard Struber:
"The expectation was so different today but in the end we have to be super happy with a point because the performance was really bad, especially after our performance against Watford last week in the FA Cup.
"The difference in levels between this and then was too big, but of course we could see that they have a new manager and every one of their players was out of their comfort zone, and we could feel that - and we couldn't deal with it.
"We lost so many second-ball fights, we were not good in possession or in transition - we could find no control in our game.
"When we won the ball, we then lost the ball. It was not our standard and that made me very unhappy.
"We were not strong enough, we were not right with the diagonal balls, we were too stressed in our decision-making - this was not Bristol City, and the players said in the dressing room afterwards we were rubbish. They are an honest group.
"It is the same story about inconsistency. We can't stay on the higher level from game to game.
"At least Radek Vitek gave a good performance. He is reliable and good with his decisions and we were happy with him.
"I was also happy with how we defended our box. It's a nil goals against, which is something to be pleased with, but our overall performance today was not the level we expect."
