The Mirror says Newcastle boss Pardew and Sunderland counterpart O'Neill clashed on the touchline and were involved in bitter exchanges in the days after a controversial clash between the clubs in March - casting doubt on the relationship between the two men.
But the pair had a face to face chat when they met at a League Managers' Association function and have now consigned the ugly incident to history.
Diplomatic O'Neill has been complimentary about the job Pardew has done on Tyneside, even going as far as saying the huge leap into the top five that Newcastle made last season is the sort of progress he wants to emulate at their arch-rivals.
And Pardew admits that "silly things were said" and that it all got rather "unsavoury" in the heat of the moment.
He has also conceded that he could have been "a bit more grown up about it," and that Sunderland's bench handled the pressure better.