Monaghan may have been the pacesetters in Division Two from the start of the league, but it all came seriously apart for them in this final game as Westmeath came with a late flourish to deservedly book their place in the final.
Westmeath started brightly and had Monaghan under early pressure with a goal by Denis Glennon after 15 minutes putting them four points ahead.
To their credit though Monaghan rallied and regained control to hit six points without reply between the 19th and 31st minutes to leave the half-time score Monaghan 0-9 Westmeath 1-4.
Within two minutes of the resumption Vincent Corey extended Monaghan's lead to three, but thereafter the storm broke again and Monaghan came under increasing pressure as Martin Flanagan, who had been introduced as a substitute shortly before the break, began to orchestrate matters for the Lake County.
He fired over two excellent points, one from distance, but more crucially he wrestled the midfield advantage from Monaghan and in the process created the level of possession that saw his side turn the game around with four unanswered points in the space of 22 minutes to go from being three behind to one in front.
Even then all was not lost for the home side as a draw would suffice to see Monaghan through to the final.
And when Rory Woods curled over an excellent point on the half-hour following good work by Eoin Lennon, Monaghan looked to be back on track.
However, that was as good as it got as Westmeath retook the initiative with Martin Flanagan breaking up a promising Monaghan counter attack to fire over the lead point two minutes from the end of normal time.
And the same player also had a hand, along with Denis Glennon, in setting John Smith up for the score that gave Westmeath a two points margin at the final whistle.