Jaden Schwartz had a goal and two assists, and Philipp Grubauer made 19 saves for the Kraken (4-6-1), who won for the first time in three games.
"It's an honor, it's really cool," said Eberle, who scored a natural hat trick. "I have a couple [of hat tricks] but this one for sure, you get the first in Kraken history, in this arena, it's pretty special. I'm not going to lie, when it went in, I definitely thought about it. It's a neat moment, and it's part of history."
Tage Thompson and Kyle Okposo scored, and Dustin Tokarski made 33 saves for the Sabres (5-4-1) in their first game after trading Jack Eichel to the Vegas Golden Knights earlier in the day.
"Think we were just getting outmuscled on pucks and beat to loose pucks," Thompson said. "I think we gave up too many opportunities against. I think really just a little too spread out. We weren't as tight in the D-Zone, not supporting each other enough out there. I think we had flashes of good stuff, but we got to be able to connect it for a full 60."
The Sabres sent Eichel to the Golden Knights for forwards Peyton Krebs and Alex Tuch, a top 10 first-round protected pick in the 2022 NHL Draft and a second-round pick in the 2023 NHL Draft. The Golden Knights also received a third-round pick in the 2023 draft.
"Obviously we addressed [the trade] in the morning," Tokarski said. "But you know, it's business time. Game day and I'm sure guys will think about it and talk about it after now, but we knew we had a job to try and do and that was our focus today."
Morgan Geekie scored his first goal in 10 games at 15:42 of the first period on a one-timer just after a Seattle power play ended for a 1-0 lead.