The wet conditions made it difficult for either team to play expansive rugby, but both battled hard to control the territory with good kicking games.
It was a game where penalty count proved key, with almost every point scored by both teams coming from the tee.
Letterkenny opened the scoring when fly-half Daffyd Green kicked the first of his penalties from just outside the 22, before Monaghan fullback Lorcan McGillian hit one in reply,
Monaghan's Gerard Treanor then dropped back into the pocket and slotted a drop goal from outside the 22 to nudge his side into a 6-3 lead, before a 45 metre penalty from McGillian put them 9-3 clear at the break.
Letterkenny's Green then had the chance to narrow the gap, and he took advantage from the tee by nailing another penalty.
However, the range of the boot of Monaghan's McGillian proved to be the difference, and he stepped up to have another successful crack at goal, again splitting the posts from 45 metres.
Green kicked another 3 points for Letterkenny which made it 12-9, but McGillian again made Letterkenny pay for any error inside their own half. His final and decisive kick, this time from 40 metres, made it 15-9.
It set up a tense finish, and although Letterkenny knocked at the door, the Monaghan defence held firm and they were crowned Gordon West Cup winners for 2023/23.
Monaghan
15-9: Lorcan McGillian; Andrew McPhillips; Evan Rutledge (C); Gareth Graham; Ryan Mohan; Gerard Treanor; Josh Graham
1-8: Ciaran McKenna; Malcolm Allister; Chris Brady; Ronan McKenna; Rob Lees; Shane McKenna; Graham Crawford; Marc McArdle
Replacements
Jamie Sherlock; Richard Carleton; Maitiu McArdle; Darren Berry; Carl Foentjies
Letterkenny
15-9: Peter Scott; Kieran Sasiadek; Daniel Faulkner; Cody Lafferty; Callum O'Hagan; Daffyd Green; Ben Hopkins
1-8: Cormac McMeniman; Jack Speer; Chris Digimas; Jack Kennedy; Ciaran Clarke; Ben Scott; Adam Bratton; David Brown
Replacements
Eoin Patterson; Barry Laverty; Martin Molloy; Michael Rankin; Tony McBride