John Askey’s side twice held the lead only for the home side to draw level before turning the game on its head to race into a 4-2 advantage in the second half and add a fifth late on.
Joe Grey handed Pools the initiative when heading in from Emmanuel Dieseruvwe's header back across goal before Olly Sanderson levelled the scores just after the half hour when finishing well at the near post.
Pools regained the lead when Callum Cooke curled a delightful effort into the top corner – a lead they would hold until midway through the second half before the hosts flipped the script.
Canice Carroll headed in a second equaliser for Oxford after Pools failed to clear their lines from a free kick and the Hoops took the lead almost immediately from the restart when capitalising on a cheap turnover in possession through Josh Ashby.
The home side weren’t done there, though, as they completed a seven minute blitz when Pierre Fonkeu pounced on an untimely error from Emmanuel Onariase to race clear and slot in a fourth before the Cameroon midfielder added a fifth late in the game to compound Hartlepool's misery.
And here is how Pools were rated on deflating afternoon in Oxford:
1. Pete Jameson - 5
Was largely untroubled in the first half barring the goal, which was a well-taken finish. Beaten four times in the second half. Not helped by those in front of him. Might have done better with the fifth. Photo: FRANK REID
2. Charlie Seaman - 5
Did well in the first half and was a threat on the right. Came close when gambling in the box to meet a fumbled cross and firing over. Had the beating of his markers. Put in one excellent cross in the second half but did leave Hendrie a little exposed behind him. Photo: FRANK REID 2022
3. Luke Hendrie - 4
Needlessly gave away possession which led to a quickfire third for the hosts. Had been fairly assured up until that point. Put in some decent crosses in the first half including the one which led to the opener. Mistake rocked him in the final 30 minutes. Picture by FRANK REID Photo: Frank Reid
4. Emmanuel Onariase - 4
Looked in complete control for spells in the first half - even able to play as high as the halfway line at times. Like the rest of the defence he struggled after the break. An untimely, and unfortunate, slip for Oxford’s fourth but, ultimately, a costly one. Picture by FRANK REID Photo: Frank Reid