As the clock ticked past the 70th minute, the thought of extra-time began to loom large at the end of a half that saw momentum shift back and forth between the two teams.
Five times in the second half either Westmeath or Derry forged a point clear, but never once in ordinary time did a lead stretch beyond the minimum.
Then, in the first minute of injury-time – four minutes that were required chiefly for the removal of Derry forward Raymond Wilkinson, who was transferred to hospital with a potentially serious knee injury – the vital breakthrough came.
Derry had looked marginally the more probable winners because of the manner in which they controlled possession and the dominance they enjoyed at midfield throughout the second half.
Making that dominance count on the scoreboard was the challenging part, however.
But when their progressive 19-year-old midfielder Ryan Bell pressed forward to take a pass from James Kielt and fire over Derry's 16th point, it felt like the game's significant surge.
Within a minute Kielt had nailed his fourth point of the afternoon and Derry felt the liberation that had eluded them throughout the second half.
The blood was coursing through their veins when Emmet McGuckin, one of two substitutes introduced in the 57th minute, contested a speculative delivery from the other substitute Ciaran McFaul and put pressure on goalkeeper Gary Connaughton.
Connaughton managed to keep out McGuckin's initial effort, but the young Magherafelt man reacted quickest to the rebound for the game's only goal and the deal was sealed for Derry's first league title since they claimed Division 1 in 2008.
McFaul added a further point for good measure, but the six-point margin of victory did not tell the true story of this game.
The open nature of the contest – 34 scores in all – reflects a certain twilight zone that these league finals tend to exist in. They lack the intensity of league matches on heavier, tighter pitches in February and March and are far removed from the type of mindset that teams bring to championship.
Still, Derry manager Brian McIver said "it would have been an absolutely horrible game to have lost because I thought over the course of the game we were just about the better side but we couldn't seem to get away from them."
It was an accurate assumption to make. McIver has done an impressive job since assuming control and Derry played with a degree of patience here that served them well.
Their movement of the ball through the hands of players like Sean Leo McGoldrick, Enda Lynn, Mark Lynch, Charlie Kielt and Benny Heron wasn't always ambitious, but it helped them to retain control for longer spells than Westmeath.
In James Kielt, they had the game's quality player. Eoin Bradley did a lot of early damage on Kevin Maguire before the Westmeath defender recovered admirably, but it was Kielt who provided many of Derry's pivotal moments, his first two points among the three that closed a three-point lead built up by Westmeath during a period of second-quarter dominance that saw them come from 0-6 to 0-2 down to lead by 0-10 to 0-7 in a 13-minute spell.
Much of that dominance was predicated on some superb fielding and productivity from John Heslin, who eclipsed Patsy Bradley.
One of his frees from 45 metres got the ball rolling for Westmeath and they followed up with points from just about everywhere and everyone to underline the impression that their success in achieving promotion was down to much more than the poor quality of some of their opponents.
With Maguire getting tight on Eoin Bradley and half-forward Ger Egan making his presence felt, Derry were forced into retreat.
Westmeath hadn't led at half-time in any of their previous seven league games so a three-point advantage was strange territory for them as the interval approached.
But Kielt's intervention with points either side of a Wilkinson effort ensured parity, 0-10 each, at the break and that curious sequence for Westmeath remained.
Westmeath waited until the 52nd minute to introduce Dessie Dolan, but his impact was telling with three points, the first within three minutes of his arrival, to peg back a 0-12 to 0-11 lead that Derry enjoyed thanks to a Benny Heron '45' that should never have been awarded after Heron's initial shot clearly went wide. The umpire felt he saw a Westmeath touch, however.
Dolan then put Westmeath in front when he clinically finished a sweeping move initiated by Connaughton's quick kick-out after Eoin Bradley had blazed wide at the other end.
McIver made a big call in withdrawing Eoin Bradley on 57 minutes just after that wide, but his replacement McGuckin repaid the faith shown in him by the manager.
Patsy Bradley and Bell dominated midfield after the break while McGoldrick dropped in behind them to telling effect as the extra man created by Westmeath's sweeper system.
Westmeath will be disappointed to have lost by so much, but manager Pat Flanagan acknowledged the progress made over the last few months.
"The big thing is that everyone had us written off two years ago when we were in Division 3. People expected us to go to Division 4 and certainly last year no one expected Westmeath to even survive in Division 2. So we are building and building quite quickly," he said.
He admitted that slow starts in all their games are something they have to address. "I was getting worried, I thought we were actually going to be ahead at half-time!" said Flanagan. "It's something we have been working on. Ironically, most of the games we have been playing against a strong wind early on; whether you can put it down to that or not I am not sure.
"The work rate it takes to get back (is immense) and on a big pitch like this it tires the guys out. It is a factor we need to work on."
Scorers – Derry: E McGuckin 1-1, E Bradley (2fs), J Kielt 0-4 each, R Bell (1f) 0-2, G O'Kane, SL McGoldrick, E Lynn, D Heavron, B Heron (f), R Wilkinson, C McFaul 0-1 each. Westmeath: J Heslin 0-5 (4fs), D Dolan 0-3, G Egan, D Glennon, C McCormack 0-2 each, C Curley 0-1.
Derry – E McNicholl 7; A McAlynn 6, C McKaigue 7, G O'Kane 7; C Kielt 7, M Lynch 7, S L McGoldrick 8; P Bradley 8, R Bell 8; D Heavron 7, J Kielt 9, E Lynn 8; B Heron 6, E Bradley 7, R Wilkinson 7. Subs: C Devlin 6 for Wilkinson (42); C McFaul 7 for Heavron (57), E McGuckin 7 for Bradley (57), L Kennedy for Heron (73).
Westmeath – G Connaughton 6; J Gaffey 7, K Maguire 7, M McCallon 6; D Harte 7, P Sharry 6, J Dolan 7; D Duffy 6, J Heslin 8; G Egan 8, C McCormack 7, K Martin 6; D Corroon 6, C Curley 6, D Glennon 7 Subs: Dessie Dolan 8 for Martin (52), K Gavin for McCallon (66), Damian Dolan for Corroon (69), L Smith for Curley (72).
Ref – C Lane (Cork).