Chalk Off Meaning

(idiomatic) To record a score or event, as if on a chalkboard.

Example: 2013, Daniel Taylor, Andros Townsend calms England's nerves in taming of Montenegro (in The Guardian, 11 October 2013)[1]
  Yet Wayne Rooney scored at a good time, three minutes after the restart, to soothe any gathering nerves and the night can ultimately be chalked off as one of the finest occasions of Hodgson's 17 months in the job.