Manawatu replied after some magic Tomasi Cama footwork at the 30-minute mark put winger Asaeli Tikoirotuma into space and over for the try.
Cruden and Semple swapped penalties, and the lead, with Semple having the last say going into halftime to give Counties-Manukau a 19-18 lead.
Counties-Manukau played the territory game to perfection as the second half began, and Manawatu continued to concede kickable penalties which Semple duly dispatched to edge out to a 25-18 lead 10 minutes after the restart.
Counties defensive pressure continued to stifle Manawatu's attacking options, and they were rewarded after 15 minutes with an excellent try to second five-eighth Reynold Lee-Lo which was set up after Stowers pounced on the loose ball from a turnover.
The cover defence closed on Stowers, then centre Siale Piutau was taken out by halfback Aaron Smith before he had a chance to take the pass.
Lee-Lo was there to snaffle up the loose ball and score, while Smith was yellow carded and Manawatu reduced to 14 men for 10 minutes.
The only noticeable effect seemed to be for the visitors to step up their game, some incisive running and crisp passing coupled with a Cama loop-around creating enough space for Manawatu centre Lewis Marshall to dive over.
Ahead 32-25 with 20 minutes to go, Counties stayed focused on defence but couldn't go past the seven-point margin. Semple had the chance with a 45m penalty at the 75-minute mark, but missed his only kick of the match to keep Manawatu's faint hopes of a draw alive right until the final whistle.
- NZPA