Wozniacki, winner of the South Carolina tournament in 2011, will face either Madison Keys for the championship on Sunday. The fifth seeded Dane broke Martic twice in the second set to claim the win.
The victory enabled Wozniacki to maintain her streak of never having lost a set to Martic in six meetings.
WTA San Diego
'No worthy competitor' - As Swiatek hits 60 wins, what comes next?
13/10/2022 AT 08:36
The Dane put herself in control of the first set with a crosscourt forehand winner up at the net to go ahead 4-2.
She had six aces in the set.
Wozniacki grabbed another 4-2 lead in the second set but the 16th seeded Martic bounced back to level the set at 4-4. The Dane broke back and went on to close out the match.
The 28-year-old defeated her opponent in just 85 minutes to reach her first final of the season.
“I just tried to stay aggressive as much as I could and tried to make (Martic) run and make her move,” number five seed Wozniacki said at her post-match press conference.
“I just keep needing to have a positive attitude, because I can play well on this surface.
“I need to keep working on my movement and on my game so that I keep improving every week.”
Wozniacki will meet number eight seed Madison Keys in Sunday’s final.
Keys overcame Puerto Rico’s Monica Puig 6-4 6-0 in a rain-interrupted contest.
The American, who lost to Angelique Kerber in the 2015 final, was pushed throughout a tight first set before rattling off eight straight games.
(With additional reporting)
US Open
'The countdown has begun' - Williams confirms upcoming retirement
09/08/2022 AT 13:22
WTA Rome
Swiatek battles past Azarenka for 25th straight win
12/05/2022 AT 14:42