I'm remembering it in the key of C on the guitar. If we're in 4/4 it would go something like this:

Dm-2-3-4-/G-2-3-4-/C-2-3-4-/C-2-3-4-/Am-2-3-4-/Am-2-3-4-/

Em-2-3-4-/F-2-3-4-/G-2-3-4/F-2-3-4-/C-2-3-4-/C-2-3-4-/

Bb-2-3-4-/Bb-2-3-4-/C-2-3-4-/C-2-3-4-/ . . .

Remember that Ms Flack took some liberties with the meter and did not exactly sing it in straight 4/4. I pluck the strings fingerstyle and it's quite a lovely accompaniment.

note:in the 3rd & 4th measure I walk the bass note down on the 5th string resolvng to the Am chord.

ending would be . . .

(Dm) the 1st time . . .(G) ever I . .(C) saw--(G). . . (C) your face . . .(Bb) your face . . . (C) your face---(Bb). . .(C) your face

Hope this helps you.