Port took an early lead, but Hartwiger swung the match into her corner with a birdie at the par-5 eighth. She went on to win the next three holes to go 3-up and never looked back.
'I spent all week making this something not so great because I didn't want to be disappointed,' said Hartwiger, who had gone as far as the quarterfinals before in 1996 and 1998.
Hartwiger, a three-time Alabama state champion who works part-time for the U.S. Golf Association, was 1-up through 17 holes and secured the title with a par at the last while Port made double-bogey.
'After having kids, I really wasn't interested in competitive golf anymore,' said the 36-year-old Hartwiger, a mother of two from Birmingham, Ala. 'But my husband kept asking me if I had played my best golf yet. Well, I played my best golf today.'
Port, who was seeking her fourth U.S. Women's Mid-Amateur title, won two straight holes on the back nine to dig into Hartwiger's lead, but in the end it was too much to overcome.
'She made everything she putted,' said Port, 41, of St.Louis, Mo. 'I didn't make a putt all week and it caught up with me. I didn't give myself a chance. It's disappointing. You don't get here often. It wasn't meant to be. But I'm happy for her.'
Port, a high school teacher and field hockey coach, won this event in 1995, '96 and 2000.
This was the 16th Mid-Amateur, a championship for women 25 and older who have a USGA Handicap Index not exceeding 9.4. The Women's Mid-Amateur is one of 13 national championships conducted annually by the U.S. Golf Association, 10 of which are strictly for amateurs.
The 2003 U.S. Women's Mid-Amateur Championship will be played at Long Cove Club in Hilton Head, South Carolina, from October 11-16.