The Terps gave up the last five goals of the game after leading 14-10 with under ten minutes left.
The Terps will face James Madison on Sunday at 1 p.m.
The Terps will play for their fifth Big Ten championship after outscoring the Scarlet Knights 10-1 in the first half.
The Terps dropped their first Big Ten game of the season to the Nittany Lions.
Thomas has notched an assist in eight straight games after recording just one point in her first two years with the Terps.
The Terps barely maintained their perfect home record in conference play during coach Cathy Reese's 16-year tenure.
Libby May scored five goals on five shot attempts as the Terps pulled away from the Wolverines to notch their second Big Ten win of the season.
Bosco transferred to the Terps from the Quakers and will play at her former home field on Wednesday.
The Terps' shooting percentage was 35.4 percent against Syracuse — well below last season's average of 48.3 percent.
Three Terps registered their first NCAA goals in the team's first win of the season.