The 56-year-old golfer from Austin, Texas, had a 69 in the opening round. He finished stroke-play qualifying at 5-under 139.
``I knew I was going to make the cut,'' Clagett said. ``I was trying to play conservatively and then I kind of got into it.''
Next up for Clagett will be Monday's first round of match play in the event for players 55 and older. He has won the last two Trans-Miss Senior Amateurs, both in match play.
Joining Clagett as the only players under par in stroke-play qualifying was Bill Shean Jr., the 1998 and 2000 Senior Amateur champion. Shean, 59, of Hinsdale, Ill., shot a 70 Sunday to finish with a two-day total of 143.
First-round co-leader Sam Farlow, 55, of Birmingham, Ala., shot a 77. Jerry Greenbaum, 61, of Atlanta, had the day's low round with a 69. Greenbaum finished the qualifying at par 144, as did 1972 U.S. Amateur winner Vinny Giles, 59, of Richmond, Va.
Defending champion Kemp Richardson, 56, of Laguna Niguel, Calif., bounced back from an 81 with a 70 to make the cut.
``As defending champion, I thought it's best I qualify,'' Richardson said.
Also advancing to match play were 1999 Senior Amateur champion Bill Ploeger, 62, of Columbus, Ga., and 1994 and 1996 Senior Amateur winner O. Gordon Brewer, 65, of Pine Valley, N.J., who advanced through a playoff.
Brewer, the captain for the 2002 USA squad at the World Amateur Team Championship, will face 2003 USA Walker Cup captain Bob Lewis Jr., 58, of Pepper Pike, Ohio, in the first round of match play. Lewis had two-day total of 145.
The playoff will be completed Monday morning, with Gary Verble, 55, of Ponte Vedra, Fla., and Robert Fouke, 59, of Broken Arrow, Okla., competing for the final spot in the match-play field.
The first round of match play starts Monday, and the championship concludes Thursday.