Salisbury and Ram have had another brilliant season, capped by their second grand slam title at the US Open, and they came from a set down to claim a 4-6 7-6 (3) 10-4 victory in Turin.
Having let a 7-1 lead slip in the deciding tie-break at the same stage last year against Jurgen Melzer and Edouard Roger-Vasselin, Salisbury and Ram ensured they did not make the same mistake this time.
Croatians Mektic and Pavic have had a superb season and had won four of their five previous meetings with Salisbury and Ram this year, including the tightest of battles in the Wimbledon semi-finals.
A double fault from Salisbury on break point in the third game here proved costly as the second seeds lost the first set, but they stayed on level terms in the second and played a flawless tie-break.
That gave them momentum heading into the deciding match tie-break and this time they did not falter, booking a place in the final on Sunday against either French duo Pierre-Hugues Herbert and Nicolas Mahut or Spaniard Marcel Granollers and his Argentinian partner Horacio Zeballos.
Salisbury is looking to follow in the footsteps of 2016 singles champion Andy Murray who is the only previous British winner of the event.