Hartwiger, the 2001 winner of this event, had defeated three-time champion Ellen Port earlier in the day to move into the third round. Massa advanced to round three with a 1-up win in 21 holes. Hartwiger will take on Mina Hardin in Tuesday's quarterfinals.
Hardin picked up a narrow 1-up win over Marianne Towersey in the third round after cruising 5 and 4 in round two at Holston Hills Golf Club.
Tobi Probst, the stroke-play medalist, fell 4 and 3 to Sally Krueger in round two. Krueger went on to defeat Pat Milton 1-up in 20 holes in the third round. She moves on to face Monday's most impressive winner, Thuhashini Selvaratnam.
Selvaratnam pounded Brenda Williams 9 and 8 in the second round to tie the largest win event history. Port was the first 9 and 8 winner, that coming over Sue Churchich in 2001.
Selvaratnam then bested two-time winner Carol Semple Thompson, 4 and 2. This was the first match Selvaratnam had been extended beyond the 12th hole. Semple Thompson had advanced with a 3 and 2 win over Marilyn Hardy.
'I just wanted to come out and play the best I could,' said Selvaratnam. 'I wasn't looking to set any records.'
The two big winners in the third round will square off in the quarterfinals. Virginia Grimes, the 1998 champion, handed Julie Carmichael a 7 and 5 defeat, and moves on to face Lisa Desimone, a 5 and 4 winner over Sandy Jocoy.
'Whatever happens from here on out, I can't complain,' said Grimes, who is recovering still from two back surgeries and another to her neck. 'I'm glad to be where I am and to be approaching another match.'
The final match will pit Corey Weworski against Patricia Cornett. Weworski, who outlasted Andrea Kraus 1-up in 20 holes in round three, also went 20 holes in her first match when she beat Joan Garety.
Cornett earned a 3 and 2 decision over Patty Moore to move to the quarterfinals. She had picked up a 2 and 1 win over Claudia Pilot in the second round.
The quarterfinal and semifinal rounds will be played on Tuesday, with the 18- hole final to be contested on Wednesday.
The Women's Mid-Amateur is one of 13 national championships conducted annually by the United States Golf Association, 10 of which are strictly for amateurs.
Second Round Results (Round of 32)
Pat Milton, Akron, Ohio def. Sherry Herman, Marlboro, N.J. 1 up
Carol Semple Thompson, Sewickley, Pa. def. Marilyn Hardy, Houston, Texas 3 and 2
Thuhashini Selvaratnam, Sri Lanka def. Brenda Williams, Minnetrista, Minn. 9 and 8
Andrea Kraus, Baltimore, Md. def. Shannon Ogg, Seattle, Wash. 19 holes
Corey Weworski, Carlsbad, Calif. def. Joan Garety, Rockford, Mich. 20 holes
Patricia Cornett, Mill Valley, Calif. def. Claudia Pilot, Austin, Minn. 2 and 1
Patty Moore, Charlotte, N.C. def. Kareen Markle, Boise, Idaho 19 holes
Kathy Hartwiger, Birmingham, Ala. def. Ellen Port, St Louis, Mo. 1 up
Julie Massa, Holt, Mich. def. Julie Garner, Winter Park, Fla. 21 holes
Mina Hardin, Ft. Worth, Texas def. Debbie Adams, Biltmore Forest, N.C. 5 and 4
Marianne Towersey, Newport Beach, Calif. def. Dawn Woodard, Cartersville, Ga. 2 up
Julie Carmichael, Indianapolis, Ind. def. Kerry Postillion, Burr Ridge, Ill. 19 holes
Virginia Grimes, Montgomery, Ala. def. Natalie McNicholas, Tulsa, Okla. 3 and 2
Sandy Jocoy, Agoura, Calif. def. Lisa Anderson, Stoneham, Mass. 3 and 2
Lisa DeSimone, Carmel, Calif. def. Jessica Soltes, Rancho Mirage, Calif. 2 and 1
Third Round Results (Round of 16)
Sally Krueger, San Francisco, Calif. def. Pat Milton, Akron, Ohio 20 holes
Thuhashini Selvaratnam, Sri Lanka def. Carol Semple Thompson, Sewickley, Pa. 4 and 2
Corey Weworski, Carlsbad, Calif. def. Andrea Kraus, Baltimore, Md. 20 holes
Patricia Cornett, Mill Valley, Calif. def. Patty Moore, Charlotte, N.C. 3 and 2
Kathy Hartwiger, Birmingham, Ala. def. Julie Massa, Holt, Mich. 5 and 4
Mina Hardin, Ft. Worth, Texas def. Marianne Towersey, Newport Beach, Calif. 1 up
Virginia Grimes, Montgomery, Ala. def. Julie Carmichael, Indianapolis, Ind. 7 and 5
Lisa DeSimone, Carmel, Calif. def. Sandy Jocoy, Agoura, Calif. 5 and 4
Pairings for the quarterfinal round of match play Tuesday at the 2004 U.S. Women's Mid-Amateur Championship at the 6,228-yard, par-72 Holston Hills Country Club course:
8:15 a.m. Sally Krueger vs. Thuhashini Selvaratnam
8:30 a.m. Corey Weworski vs. Patricia Cornett
8:45 a.m. Kathy Hartwiger vs. Mina Hardin
9 a.m. Virginia Grimes vs. Lisa DeSimone