Latch Onto Meaning

(idiomatic, transitive) To obtain, acquire or get and keep hold of something.

Example:   They latched onto the idea and gave it up only reluctantly.
2011 September 16, Ben Dirs, “Rugby World Cup 2011: New Zealand 83-7 Japan”[1], BBC Sport:
  And there was time for two more All Blacks tries, first flanker Adam Thomson flopping over after a break by Jimmy Cowan, before Williams latched onto a clever cross-kick by Kahui for his second touch-down with three minutes remaining.