The sky above Healy Park had grown noticeably darker and the game had entered its final minutes when Monaghan's Conor McManus took over.
The forward has rightly been lauded for a wonder-point in the 71st minute that restored his side's three-point lead.
But it was a go-ahead free four minutes earlier that really rattled Tyrone.
The crowd in the stand tried, in vain, to unsettle the Monaghan forward as he floated a beauty of a score up into the wind and delicately over the bar.
He turned to celebrate with a fist pump and a pair of pointed fingers towards his hecklers as if to prove to them that he would not be denied.
Monaghan had won just once in their previous five championship meetings with Tyrone and the memories of their 2013 and 2015 All-Ireland quarter-final defeats by Mickey Harte's men would have begun to resurface when Connor McAliskey converted a huge 45-metre free to draw Tyrone level from three points back.
Up stepped McManus with his free and his triumphant celebration as the visitors regained the lead that they would not relinquish again.
The two-time All-Star finished the day with six points to his name with four of those scores coming in the closing minutes when Monaghan's need was greatest but he also showed why he is such an important cog in the Farney side in the first period when he was blocking shots and winning scrappy possession deep in his own half.
Red Hands fail to fire
An Ulster semi-final against Fermanagh is the reward for Malachy O'Rourke's side but Tyrone must now attempt to plot a route through the qualifiers in order to reach the Super 8s series in July.
Former Cavan and Roscommon manager Tommy Carr suggested after the game that Tyrone would not be too disappointed to miss out on a third consecutive provincial title - provided they can still engineer a way through to the group stage format.
The main focus, Carr reasoned, must be on reaching the last eight when the real All-Ireland contenders will emerge.
Red Hands manager Mickey Harte agreed that his side cannot afford any further slip ups.
"We'd always prefer to go the front door and there's a cup at the end of the front door in Ulster and we've now missed out on that so that's regrettable but there's still a second chance and we're grateful that there is a second chance," said Harte.
The biggest concern for the veteran manager in his 16th campaign in charge is that so many of his big players failed to perform.
The gamble on Colm Cavanagh's fitness did not pay off as the towering midfielder was replaced at half-time while Lee Brennan was restricted to scoring from deadballs and Mark Bradley limped off during the first half.
Peter Harte looked crestfallen to be shown a late red card and Ronan O'Neill was subbed on but was later replaced as McAliskey appeared to be the only Tyrone forward capable of scoring consistently.
"I don't think it will be hard to lift the players up," added Harte.
"They believe that they're good enough to be challenging to be in the quarter-finals so if we can get our act together, and we don't get too harsh a draw in the first instance, maybe we could rebuild a bit of momentum for ourselves again."
The deposed Ulster champions now have two weeks to prepare for the first round of the qualifier draw but Monaghan can already look forward to a semi-final battle with Fermanagh on 3 June.