Arsenault (pictured) went 0-for-3 in the first game, but had three hits in the nightcap. He missed his entire junior season with an injury.
The Mammoths improve to 19-14 overall and will be back to Waterville for next weekend's NESCAC Baseball Championships at Colby. Colby ends the season at 10-25-1.
Colby's Brooks Parker allowed just four hits over 6.2 innings of the seven inning opener. He allowed no earned runs, struck out four, and walked one.
Ben Coleman singled and walked twice in the first game for the Mules. He finished the season with a .396 batting average.
Ariel Kenney doubled twice and was on base three times for the Mammoths. Roberson had a double among his two hits and scored two runs. Thanopoulos also doubled and had two hits. Spina smacked a triple and scored twice.
The Mammoths scored twice in the first inning on a one-out single by Roberson to get things going. With two outs, Spina struck out but reached on a wild pitch and advanced to second. Kenney reached on an infield error and both runs came in for Amherst.
The Mules went ahead 3-2 with a lone run in the fourth inning. Lowensohn and Schmidt had back-to-back one-out singles. After the second out, Coleman brought Lowensohn home with an RBI single.
In the Colby sixth inning, Noah Tocci walked to start the inning, moved to second on a ground out, and scored when Conor Bruen singled and Amherst had an error.
Roberson doubled to lead off the ninth and took third on a sacrifice. Spina's sacrifice fly to center field scored the final run.