The Fightin Phils managed just two hits Monday night in a 2-0 loss in their series opener in Portland.
Mike Augliera threw eight stellar innings for the Sea Dogs to earn the win.
Severino Gonzalez (6-12, 5.12) lasted only three innings and took the loss on the mound for Reading.
Jake Fox and Carlos Alonso had the hits for the Fightin Phils. They were both singles.
The game was the first of a nine-game road trip in just a seven-day span for Reading.
The Fightin Phils (44-62) will play a doubleheader in Portland on Tuesday, with game one beginning at 6pm.