Morais’s side went into Saturday’s game with a chance of getting relegated should they have lost and Bolton Wanderers had triumphed at Burton Albion.
But the afternoon ended with the Reds moving out of the relegation zone with just their third win of Morais’s 14-match tenure.
But other permutations can see the Reds survive should they fail to win with Birmingham City and Reading not out of the relegation picture either.
Morais said: “It is one of the proudest moments I can have in my life, as the manager of Barnsley.
“I have had a lot of difficult moments and this was a special moment to share with my players. I think it is fantastic. If the league was supposed to end (Saturday), we would say, ‘we are in the Championship next season’. I want to reaffirm this next Sunday. These players really, really want to stay in this Championship and believe that they can do it and I just want our fans to believe until the end.”
On a sweet afternoon goalkeeper Jack Walton, who made his Oakwell debut, added: “It is in our hands now, which is good, and we go to Derby on Sunday confident we are going to do the job.
“At the end of the day Saturday was about getting three points. We have done that and have one massive game, one cup final left and we have to win it.
“We win that game and we stay up.”