The Leopards (10-13, 5-3 Patriot League) scored 26 points off 20 Navy turnovers and held the Midshipmen to their lowest point total since they scored 40 points in a loss to Holy Cross on Feb. 14, 2007.
Navy (3-19, 0-8) made only 4 of 16 field goal attempts in the second half and shot 36.8 percent (14 of 38) for the game. The loss was the 15th straight for Navy.
Lafayette used a 12-0 run early in the second half to lead 45-28 with 12:54 remaining. The Leopards kept the lead in double digits the rest of the game and held their largest advantage at 22 points, 55-33, with 5:44 to go.
Ryan Willen and Seth Hinrichs each scored 10 points for the Leopards, who have won four straight at home in the series.