Port beat Burke of Houston, 4 and 3. Burke is the wife of 1956 Masters and PGA champion Jackie Burke Jr.
Port is the only past Women's Mid-Amateur champion remaining in the field, and she isn't ready to go home.
'I feel like I'm a better player now than when I won my other three,' said Port, a high school teacher and field hockey coach and recent winner of her state Amateur, which she has now won five times. 'I've worked hard to improve my putting and sand game.'
Mina Hardin, 42, of Ft. Worth, Texas, moved to within two wins of returning to the championship final match Tuesday. Hardin was the runner-up a year ago.
Hardin didn't lose a hole and was 4-up after nine holes on her way to beating last year's semifinalist Sherry Herman of Marlboro, N.J., in her third round match, 3 and 2.
Among the other seven winners in the third round were Kathy Hartwiger, 36, of Birmingham, Ala., and Lisa Desimone, 29, of Carmel, Calif.
Hartwiger, a three-time state champion, won five of the first eight holes en route to her win over Lesley Stracks of Washington, D.C., 5 and 3. Desimone, who is headed back to Arizona State University in the spring, won four of the first five and defeated Adrienne MacLean of Verona, N.J., 5 and 4.
'When you get to this level in a national championship, you get a little nervous,' said Hardin. 'This is not the 'Flying Pink Lady Tournament.' Last year I was so happy to get to the final that it really didn't hit me until I got home that I had a chance to win. Now I know I can get there and maybe I should aim to win.'
Play continues Wednesday with the quarterfinal and semifinal rounds. The 18- hole final match set for Thursday.
The Women's Mid-Amateur is one of 13 national championships conducted by the United States Golf Association, 10 of which are strictly for amateurs.
The U.S. Womens Mid-Amateur Championship is open to all players 25 years or older who have a USGA Handicap Index not exceeding 9.4.