The poem begins with what the speaker calls "an unlikely match." In the light of the title—"Chainsaw Versus the Pampas Grass"— this might be a match in the sense of a fight: the battle between a chainsaw and some unruly decorative grass. As the speaker hauls out his chainsaw to do a spot of light gardening, the outcome of this "match" seems like a foregone conclusion. No way could grass fight back against a chainsaw.
In these first lines, though, the "unlikely match" could also be an unlikely partnership. Hefting the chainsaw, the speaker feels awe, alarm, and titillation at its power—emotions that make him seem like a very "unlikely match" indeed for such a singlemindedly destructive piece of equipment.
Right from the start, the chainsaw seems dangerous. The speaker personifies it, picturing it "grinding its teeth" as it waits "all winter unplugged"; it sounds frustrated and angry at its long inactivity, more than ready to leap into action again.
It's also thirsty. It "knock[s] back a quarter-pint of engine oil" like a belligerent drunk doing a shot at the bar, and an overflow of "juices" messily run down its blade into its "dry links" like dribblings into stubble. The speaker follows the course of that oozing oil as it crosses "the guide-bar and the maker's name" embossed in the metal, making it sound as if he's looking the chainsaw up and down in admiration and fear.
In short, the speaker seems in awe of the chainsaw, treating it not like a tool he's about to use, but like a dangerous guest who's been lurking in his "darkroom" all winter long. He's fascinated by the chainsaw's brusque gulpings and grindings. Perhaps he himself is not the kind of guy who grinds his teeth and knocks back a quarter-pint of anything; perhaps he'd sort of like to be. This will be a tongue-in-cheek poem about the allure—and folly—of violent power.
The speaker will tell this tale in seven irregular stanzas of free verse, without rhyme or meter. This flexible form will shift its shape to mirror his experiences.