The world number 17 took one hour and 48 minutes to beat Nishikori, who is ranked fifth in the world.

Dimitrov, 25, won the first set quickly before Japan's Nishikori won four consecutive games to level the match.

The Bulgarian then broke Nishikori in the final set - despite tweaking his ankle - to secure the title.

Nishikori has reached the Brisbane final six times but he has never won the tournament.

Elsewhere, number two seed Roberto Bautista Agut claimed his first Chennai Open title with a 6-3 6-4 victory over Russian Daniil Medvedev.

The Spaniard took one hour and 13 minutes to win in straight sets.