The game needed a moment of magic to light it up – and Marlon Pack duly delivered with a superb free-kick midway through the first half.
That was not enough to ended Pompey’s run of draws, however, which stretched to four after Sam Long nodded in the equaliser.
It was a stalemate that effectively ended any faint hopes of securing a spot in the League One play-offs.
And while John Mousinho felt the performance contained some positives, he knows that more is needed.
The Blues boss said: “It was two sides who wanted to play and a draw was probably the fair result in the end.
“In any other circumstance we’d probably think it was a good point against a team that most thought would be challenging for the top six this season, but we obviously needed the win.
“We got caught on the break a bit too much and most of it was our own doing, with some sloppy moments.
"We 100 per cent know that we need to do more to get opportunities – we can’t just rely on scoring one goal every game."
“But I didn’t really feel we were carved open and there were times we gave the ball away when there was no need.
“It’s probably a running theme for us in terms of creating chances, although Oxford are very well organised and have not conceded a lot of late.
“We 100 per cent know that we need to do more to get opportunities – we can’t just rely on scoring one goal every game.”
In a contest missing any reckless challenges from either side, it was perhaps surprising to see Pompey end with six players being booked by referee Declan Bourne.
Mousinho said: “It was interesting that we had so many yellows, when Paddy Lane has ended up on the concrete having taking a forearm to the side.
“Some of the things that went on were just bizarre – you probably saw my frustration as the game went on.
“I couldn’t really understand what was happening and nor could the fourth official, so it’s best we leave it there.”