A Late goal from Oxford full-back George Baldock denied Morecambe a second successive away win.
The Shrimps looked to be heading for the points after an early opener from Kevin Ellison.
But Baldock earned former North End favourite Michael Appleton’s side a share of the spoils with a fine individual goal just three minutes from time.
It could have been worse for the Shrimps but Ryan Edwards clearing a Patrick Hoban effort off the line and Andreas Arestidou saving sharply from James Roberts’s follow up to keep a hold of the point.
Ellison gave the Shrimps the lead on 11 minutes with his 50th goal for the Shrimps.
Jack Redshaw created the opening with a right-footed shot from 10 yards out that was well saved by Ryan Clarke but Ellison was in the perfect place to slot home the loose ball from six yards out.
From then on, Morecambe caused the home side all sorts of problems.
Ellison flashed a shot inches wide of the right-hand post on 13 minutes and Jamie Devitt volleyed wide from the edge of the area.
The Shrimps looked to have been denied a penalty on 23 minutes when Redshaw was bundled over the box after a well worked free-kick saw him looked set for a free run on goal.
It proved to be a turning moment of the half as Appleton’s side began to take charge.
Danny Hylton fired straight at Andreas Arestidou on 36 minutes from 10 yards when he should have done much bette.
Then Josh Ruffells headed against the Morecambe crossbar from Alex McDonald’s right-wing cross with Arestidou beaten.
After a good start, the Shrimps were left hanging on but moved a point clearer to League Two safety.
Oxford: Clarke, Baldock, Mullins, Wright, Skarz, Collins, Ruffels, O’Dowda (Roofe 65), Hoban, McDonald (Roberts 79), Hylton (Gnanduillet 64). Subs not used: Ashdown, Rose, Long, Dunkley
Morecambe: Arestidou, Parrish, Hughes, Edwards, Beeley, Fleming, Wright (Goodall 58), Wilson, Devitt (Amond 73) Redshaw (Mullin 79), Ellison. Subs not used: Stewart, McGowan, Kenyon, Williams‑