Alexander had nine points in the first quarter as Cooperstown opened with a 21-9 run.
Jordan Manikas and Grant Davine contributed 11 and 10 points, respectively, for the Hawkeyes (8-7), who host Frankfort-Schuyler on Jan 31.
Mitchell Scherer scored a team-best 18 points for Herkimer.
Davenport 56, Gilboa 49
Matthew Finne scored a game-high 20 points to lead undefeated Davenport to a Delaware League win on the road.
Finne hit two threes en route to eight points in the second quarter, when Davenport (12-0) outscored Gilboa, 19-11, to take a 26-21 lead into halftime.
“They’re a hard team to focus on one guy,” Gilboa coach Andy Dumas said. “They’re pretty balanced.”
Kyle Moorby contributed 11 points for Davenport.
Christian Cooper’s 19 points paced Gilboa, which received 10 rebounds from Zach Perry.
Gilboa hosts Hunter-Tannersville on Monday.
Margaretville 38, Roxbury 37
Cooper Reither hit a foul-line jumper at the buzzer to lift visiting Margaretville to a Delaware League victory.
Roxbury (2-8) missed the front end of a 1-and-1 free throw opportunity with 6 seconds left.
“They threw an outlet pass off the rebound and we kind of missed the steal,” Roxbury coach Tom Faraci said. “It was one of those bang-bang plays. Reither just shot it up from free throw line and it went in.”
Matt Van Valkenburgh’s 11 points paced the Blue Devils, who received eight points apiece from Reither, Dylan Shaffer and Kyle Short.
Matt Faraci scored a game-high 15 points for the Rockets, who host Jefferson on Jan. 31.
SK 61, Windham 39
Tyler Lamport scored a game-high 19 points to lead host South Kortright to a victory in the Delaware League.
Griff Metzko contributed 18 points for the Rams, who took a 35-14 lead into halftime.
David Saunders scored a team-best 16 points for Windham.
South Kortright (12-3, 9-2) hosts Downsville on Jan 31.
H-T 53, Downsville 51
Jake Davis scored the winning field goal with 3 seconds left to lift Hunter-Tannersville to a Delaware League win at home.