The top-seeded Murray gained his 39th ATP title match berth when, after Murray built a 6-4, 2-0 lead, fifth-seeded Kei Nishikori retired due to a knee injury. Dimitrov eked out a 6-3, 5-7, 7-6 (7-5) semifinal win over Marcos Baghdatis.
Dimitrov had 12 aces and lost his serve twice but handled both break-point chances Baghdatis had in the third set. Baghdatis was up 4-2 and then 5-4 in the tiebreaker but Dimitrov reeled off three straight points to win the match.
Murray had lost just eight points -- including losing a break -- on serve and had three points in winning half of the points off Nishikori's serve when the match was stopped.
Murray was a 6-4, 6-4 winner over Dimitrov in a 2011 match in Thailand -- the pair's only previous ATP meeting.
Murray, looking to repeat as Brisbane champion, has 24 titles.
The Brisbane International champion will collect $78,800 with the runner-up winning $41,540. Baghdatis and Nishikori each take home $22,500 as semifinalists.