Anthe Nijziel's third-quarter goal started the scoring for the Hawkeyes.
Maura Verleg buried the winner in the 3rd quarter.
The Terps and Hawkeyes have met many times over the years, perhaps no time more dramatic than their NCAA tournament clash in 1999.
Riley Donnelly and Taylor Mason are among the Terps' biggest penalty corner threats.
Freshmen Maura Verleg and Anna Castaldo scored their first career goals Friday evening.
The Terps never ranked lower than No. 4 in the NFHCA poll last season.
Bibi Donraat scored the winner in the 58th minute.
Barraco made seven saves for the Nittany Lions as the Terps dropped their second straight game.
The senior has four points in three games.