The Terps' sweep of the Bears was their first road sweep under coach Rob Vaughn.
The Terps were at a deficit for the first time this season but home runs from Max Costes and Matt Shaw pushed them to 3-0.
The Terps scored four runs in the first inning, followed by a solo home run from Bobby Zmarzlak in the third to take control of the matchup.
Dean pitched seven shutout innings against the Bears in the Terps' 2022 season opener.
The Terps will open their season with a challenge at Baylor.
Vaughn's contract came into effect July 2020 and will run through June 2026, securing the head coach that brought the Terps to the NCAA tournament for the first time since 2017.
Cowles was the second and final Maryland player taken in the draft.
The Terps' former ace is the highest draft pick from Maryland baseball since Brandon Lowe in 2015.