Navy opened the second half with a 20-6 run to build a quick 20-point lead and never relinquished command after that in a 79-57 upset of Army on Saturday afternoon in a Patriot League game in West Point, N.Y.
Navy forward Worth Smith scored a game-high 23 points as the Midshipmen (8-15, 3-9) snapped a six-game losing streak and gained a split of the two regular-season meetings with Army.
Army won in Annapolis, Md., on Jan. 11.
Since that point, Navy had won only once, beating Bucknell on Jan. 15, until Saturday.
The win moved the Midshipmen out of the conference cellar after Lafayette lost to Boston University earlier in the day to fall to 2-10 in conference play.
Forward Tanner Plomb scored 17 points to lead the Black Knights (12-11, 8-4), who lost for the third time in their last seven games.
Navy led the final 38 minutes after taking a 5-3 lead on Smith's two free throws with 18 minutes to go in the first half, but the Midshipmen were up only 37-33 at intermission.
Their lead was just six points, 42-36, nearly four minutes into the second half before Navy began its decisive run. In about a three-minute span, the Middies went on an 9-0 spurt for a 51-36 lead before continuing on to a 59-39 advantage with 12:45 left in the game.
Poor shooting in the second half doomed the Knights. They were only 8-of-26 in the final 20 minutes after going 10-of-21 from the field in the first half.
Navy shot 50.7 percent for the game (30-of-57).