Carew will face Haverfordwest in the final of the Duggie Morris Cup after they overcame a spirited performance by Lawrenny.
Set 124 to win, the home side fell an agonising nine runs short of the victory target despite having home advantage.
Carew's total of 123-5 was down to teamwork as Ian Sefton top scored with 35, with Simon Wood not far behind in his innings of 30. Nick Scourfield continued his fine form for the season with 19 and Wayne Cannon blasted the same score towards the end of the innings.
For the homesters, Steve Lewis, James Buckle and Ian Jenkins took one wicket apiece.
In reply, Lawrenny were always up with the run rate, but just couldn't sneak ahead of it as they lost eight wickets in their total of 114.
Steve Lewis and Buckle both showed their all-round credentials with scores of 28, while James Phillips struck some fine shots in his unbeaten 20.
Although it was a valiant effort, it wasn't quite enough as Robert Scourfield led from the front with 3-23, while Simon Wood took 2-16 alongside Rhys Davies and Ceri Brace, who both took one wicket.
In the other semi-final played at Hook, the home team scored 109-6 as only Mick Haltam came to grips with the Haverfordwest bowling, striking three 6s and two 4s in his unbeaten 51.
The total was no match for the Town as they romped to a 10-wicket win after Danny Potter smashed an unbeaten 54 and Richard James 41.