Fantilli, who was the No. 3 pick in the 2023 NHL Draft, gave the Blue Jackets a 4-3 lead on a one-timer through traffic at 8:43 of the third period.
Patrik Laine, Johnny Gaudreau and Kirill Marchenko each had a goal and an assist, and Ivan Provorov and Damon Severson each had two assists for Columbus. Elvis Merzlikins made 23 saves.
Zemgus Girgensons, Owen Power and Zach Benson scored for Buffalo. Ukko-Pekka Luukkonen made 28 saves.
Laine scored his third goal of the preseason at 6:15 of the first period to give the Blue Jackets a 1-0 lead. Emil Bemstrom then scored his third of the preseason on a power play at 9:04 to make it 2-0.
Girgensons cut it to 2-1 at 11:38.
Gaudreau gave Columbus a 3-1 lead 23 seconds into the second period.
Power cut it to 3-2 at 13:53, and Benson tied it 3-3 at 18:45.
After Fantilli put Columbus back in front, Marchenko scored an empty-net goal at 18:32 of the third for the 5-3 final.
