Reading won the series opener but Trenton rebounded with three consecutive wins.
Trailing 5-4, the R-Phillies had runners on first and second with one out in the top of the ninth. Darin Ruf, who had homered in the sixth inning, bounced into a series-ending 6-4-3 double play.
Reading left eight runners on base and was 3-for-8 with runners in scoring position. Trenton was 1-for-3 with runners in scoring position and left one runner on base.
Starter Adam Morgan took the loss, allowing five runs on five hits in six innings. The decisive run came on a sixth-inning solo homer by shortstop Addison Maruszak, his second in the series. A two-run homer by catcher JR Murphy keyed a three-run third inning that broke a 1-1 tie.
Third baseman Cody Asche was 2-for-4 with an RBI and finished as Reading's leading hitter, batting .429.