Slowly But Surely Meaning

(idiomatic) In a slow, yet careful manner.

Example: 2011 January 25, Phil McNulty, “Blackpool 2 - 3 Man Utd”[1], BBC:
  From then on the visitors, inspired by the composure provided by Ryan Giggs after he came on for Darron Gibson at half-time, managed to unscramble their senses to slowly but surely overpower gallant Blackpool.