。
I barely made it in time for the last train.
Literal
I [topic-は] last-train [for-に] barely [possessive-の] point [at-で] made-in-time.
すれすれ ('barely, by the skin of one's teeth') describes an extremely narrow margin — すれすれのところで is a set phrase meaning 'just barely.' 間に合う ('to make it in time') is an essential everyday verb. 終電 is the common shortening of 終電車.