Jackson, the Belton, S.C., player preparing for her season year at Furman, will face Becky Lucidi of Poway, Calif., on Saturday in the 36-hole final on the Sleepy Hollow Country Club course.
Lucidi, who will be a senior at Southern California, beat Australia's Lindsay Wright 3 and 2, closing out the match with a 16-foot eagle putt on the 16th hole.
'Today and yesterday, I played the best golf of my life,' Lucidi said. 'Match play comes down to one thing -- heart -- and I know I always give it everything.'
After a delay of nearly two hours because of rain and lightning, Jackson beat Martinez with an 8-foot birdie putt on the first extra hole. Play also was delayed for nearly an hour earlier in the day.
Jackson won the final three holes of regulation, going par-birdie-par, to force the playoff.
'During the delay, I had time to realize what I did,' Jackson said. 'I had a good feeling that I'd win the playoff.
'Getting two birdies on the last four holes will certainly give me momentum for tomorrow. I really feel sorry for my dad [Terry], who is my caddie. I'm sure his nerves are shot by now.'
Martinez will be a freshman at Auburn.
'I can't believe what happened,' Martinez said. 'Before the tournament started, I never gave any thought to winning it. To get this close and for this to happen. Unbelievable. I think I lost my focus.'