The 18-year-old second seed recovered impressively after failing to close out the opening set when serving for it, having earlier held a set point at 5-2.
Jovic stayed composed, however, producing a forehand winner to create three more opportunities in the 10th game before taking her third chance.
Bucsa could not find a response in the second set, with Jovic taking control after the score reached 1-1 and winning the next five games to complete a straight-sets victory.
Jovic captured her maiden WTA title in Guadalajara 12 months ago and has described her first title defence as a challenging experience.
"There were so many ups and downs, but I was able to just hold firm on my serve and get through in straights. [This week as defending champion], there have been a lot of different things to deal with, to adjust to, and I've just been having a positive mindset through it all," said Jovic.
She will face world No. 60 Peyton Stearns in the final, with the pair meeting for the first time. The contest will mark Jovic's second final of the year after she lost to Elisabetta Cocciaretto in Hobart.