WATERVILLE — A big win, a signature win, a must-win. By any name, for a still-fledgling hockey team, it was a significant win for the first-year Waterville/Winslow co-op on Saturday night at Colby College’s Alfond Rink.

The Kennebec RiverHawks rallied back from a two-goal, third-period deficit, leaping over the final hurdle with junior Cooper Hart’s goal 1:28 into overtime for a thrilling 4-3 win over Hampden Academy, the No. 1 team in Class B North. Tom Tibbetts finished with a goal and three assists for the RiverHawks (4-4-0), who got a 20-save effort from sophomore Bryce Gunzinger for the victory.

No save was bigger than Gunzinger’s five-hole stop on Hampden’s Marcus Dunn, who was bidding to complete his hat trick on a breakaway in the final three seconds of regulation, sending the game off to overtime — where Kennebec won for the third time already this season.

“It’s a huge win,” Tibbetts said. “A huge win. We’re back to .500 and we’re back on track now.”

Dunn’s second goal of the game came at 1:13 of the third period, answering Tibbetts’ power-play goal in the final minute of the middle stanza, by hammering home Sam Economy’s cross-ice pass to the right circle to build a 3-1 lead for Hampden (6-2-0). When Kennebec had every reason to fold its collective tent and move on, the RiverHawks simply refused to go away.

Tibbetts first set up defenseman Chase Wheeler’s redirected drive to make it 3-2 at the 3:38 mark of the third, and he then found Logan Denis with a nifty little cross-crease pass on the power play to knot the score with under 10 minutes remaining in regulation.

“We’re playing pretty well right now. We’re starting to come together as a team,” Tibbetts said. “Right there at the end of the second period, we got some momentum. We’d been firing the puck at the net all game, and we finally got one.”

But the stage still wasn’t set for Hart’s game-winning goal, not after Hampden penned the RiverHawks in their own zone for more than a full minute to begin the overtime session. Twice the Broncos threatened in the slot area, only to have their centering passes just miss connections or have a shot blocked by Kennebec defensemen.

“We never had the thought in our head that we were going to lose this game,” Hart said.

And when Tibbetts finally was afforded space in the middle of the ice, he turned the transition game in the other direction — finding Cody Pellerin with an outlet pass that Pellerin turned into a shot on Hampden freshman goalie Cooper Ryan. Ryan made the initial stop on Pellerin, and another on Hart’s first rebound try.

Ryan, who ended up making 39 saves, couldn’t stop a second shot from Hart.

“I was expecting a rebound, but when he gives rebounds they bounce in really hard spots to get them,” Hart said. “I was just in the right spot to put it in. It’s big.”

“It takes character, and that’s what I saw from my guys today. That’s what’s important,” Kennebec head coach Jon Hart said. “This has to be our signature win. It has to be. We know that they have a few guys that can play, and I think they saw that we have a few guys who can play, too.”

For Hampden, it was a difficult loss after squandering a two-goal lead and narrowly missing out on chances to extend its lead.

“They just outplayed us, outhit us and they got momentum and played hard. They’re a good hockey club,” Hampden head coach Eric MacDonald said. “They had a good game plan, they executed and we didn’t execute enough.”

Things couldn’t have gotten off to a worse start on the night for the RiverHawks, who watched as Dunn scored just 19 seconds into the game to give the Broncos a 1-0 lead they would take into the first intermission.

Economy forced a turnover at the offensive blue line, drew both Kennebec defenseman to him along the right wing boards and then centered for Dunn, whose wrister evaded Gunzinger.

It was as though the opening goal registered how important a regular season game this was, as the next four minutes devolved into a chess match that saw the teams combined on five icing calls and a small amount of line matching from Hart.

Kennebec’s best chance to get on the scoreboard came on a late power play, which produced good looks for both Pellerin and Tibbetts but came up empty.

That came back to haunt the RiverHawks when Cooper Leland’s brilliant individual rush from the neutral zone doubled Hampden’s lead.

Leland picked the puck up and walked down the right wing, evading three separate attempts by Kennebec players to knock him off the puck, before his scalding wrister beat Gunzinger at the 3:43 mark.

“You’ve just got to keep going, keep playing,” Tibbetts said. “You just keep trying to play at a high tempo. That’s all it is.”

Travis Barrett — 621-5621

tbarrett@centralmaine.com

Twitter: @TBarrettGWC