Although Linfield could have had two players sent off in the first-half, Cliftonville manager Gerard Lyttle was in no mood to make excuses after watching his team give up the chance of an automatic European place in such limp fashion.
A disciplined, promising first-half when they did everything but score was the precursor to a second period "when we didn't come out" and Linfield's 4-0 victory was just one goal shy of their biggest ever in the Premiership against the Reds.
"It was a Jekyll and Hyde performance," said Lyttle.
"Aaron Burns scored twice but shouldn't have been on the field after his tackle on Caoimhin Bonner and the fourth official told me it was a red card offence when (last man, Mark) Haughey brought down Daniel Hughes. So those decisions went against us but how can we go from one half and then hit the destruct button in the second-half?
"Now we face potentially two cup finals (in the play-offs) to get to Europe."
The Reds must wait until next weekend to learn their fate, with their own trip to Coleraine relatively academic in the grand scheme of things.
If Ballymena United can leapfrog Dungannon Swifts into seventh place in the table, the Sky Blues will visit Solitude for a semi-final showdown but, should the Swifts hang on, Cliftonville will be granted an automatic bye to the final - where they would face either the Bannsiders or Glentoran - on account of Dungannon not having applied for the requisite Uefa Licence.
As for Linfield, the assurance of having already secured a European place and the possible distraction of a forthcoming Irish Cup final battle with Glenavon might explain why they were second best for the majority of the first-half.
The Reds threatened through Davy McDaid and Martin Donnelly but, totally against the run of play, the deadlock was broken when Burns pounced to net in the aftermath of Conor Devlin dropping a Ross Gaynor cross.
Burns made it 2-0 early in the second-half as David Healy's men took a firm grip on proceedings, with Paul Smyth and a Gaynor penalty rounding off what was, in the end, a comfortable win.
"Credit to the players, when you play poorly and go in one up it gives you a lot of belief for the second-half," said Healy. "I had a few choice words at half-time to a few players. I was well aware of how big a game it was, when you play Cliftonville you have to do your job. The tackles were flying in so it was competitive.
"We lost the game at Crusaders but what a response, that's 3-0, 4-0 and 4-0 again."
LINFIELD: Deane, Haughey, Callacher, Waterworth, Lowry, Millar (Fallon, 89 mins), Burns (Kee, 64 mins (McLellan, 71 mins)), Ward, Mulgrew, Gaynor, Smyth.
CLIFTONVILLE: Devlin, McGovern, Ives, Bonner, Flynn, Knowles, Curran (Garrett, 60 mins), McMullan, McDaid (J Donnelly, 60 mins), M Donnelly (Lavery, 76 mins), D Hughes.
Match Rating: 7/10
Man of match: Paul Smyth
Referee: Ian McNabb (Newtownabbey)