Martinez beat Hingis three month ago in Berlin on slow red clay before winning the tournament.
But on Saturday she was clearly dominated by the Swiss champion who proved more patient and smarter under difficult windy conditions.
Martinez started out strongly, breaking Hingis' serve to take a 3-1 lead.
"I was rushing a little too much so I though that I should be more patient," Hingis said later.
She fought her way back as Martinez began making more and more unforced errors. Hingis captured seven games in a row to win the first set in 34 minutes, and take a 2-0 lead in the second.
Martinez pulled back to 2-all, but Hingis kept dominating the rallies proving a little quicker and less erratic, as she captured the next four games and the match which lasted one hour, 17 minutes.
"At the beginning I was still feeling a little tired from my match ... yesterday," Hingis said on the court. "But then, I didn't want to disappoint all of you guys who had supported me all week, and I fought back hard."
Martinez said: "I was 3-1 up and I was playing good tennis, while she was not so patient. Then all of a sudden I started missing and then patience changed sides."
In the final on Sunday, Hingis will play the winner of the second semi-final between Serena Williams and Arantxa Sanchez-Vicario.
"I lost to Serena last week, so I would love to play her again," Hingis said. This is Hingis' eighth final of the year. A victory tomorrow would give her her fifth title of 2000.