The Terps held the Nittany Lions scoreless for more than 26 minutes in the second half.
The Terps allowed just two goals in the second half to win its first conference game of the season.
Daniel Kelly scored the game-winner to hand the Cavaliers their first loss of the season.
The Terps beat the Cavaliers in the NCAA tournament quarterfinals last season.
The Terps took a step forward after multiple inefficient outings.
Daniel Maltz and Braden Erksa scored four while Jack Koras added three goals in the Terps' win over the Great Danes.
Trader has made a near-seamless switch from football to men's lacrosse for the Terps.
The Terps and Fighting Irish are now tied in the all-time series, seven to seven.
The Terps fell in their first overtime game since a sudden-death winner against the Fighting Irish in 2021.
Former Terps Logan Wisnauskas and Alex Smith prevailed in first Premier League Lacrosse championship series.