Waterford — Bill Bassett normally coaches his team with calmness and composure, perhaps the byproduct of Waterford High School’s 32-1 record in its last 33 games. Think about it: How chafed can you get about things when you’re 32-1?

And then came Wednesday night at the Francis X. Sweeney Fieldhouse, when Bassett called a timeout midway through the third period. His team was losing to blood rival East Lyme, despite the absence of leading scorer and all-state guard Dev Ostrowski.

Suddenly, Bassett could have been heard at Hammonasset, his decibels perhaps only matched by equally annoyed assistant coach Tim Lineburgh.

“They were out-competing us,” Bassett said later, “and I had to let them know that.”

It worked. The sixth-ranked Lancers used an ensuing 19-2 run to finally dispatch their rivals 63-47 before more than 1,200 fans.

“I know what East Lyme has been through in the last 10 days,” Bassett said, alluding to Ostrowski’s injury. “Whatever coach (Jeff) Bernardi is doing with his team, it’s working. They brought the fight. I know an East Lyme team without Dev isn’t the same. But given that, my guys have got to match the fight the other team brings. We have the ability and natural talent to do a lot of things. But if you don’t bring that energy and you let someone out-compete you, it won’t end well.”

JJ Brennan led Waterford (17-1) with 22 points. Payton Sutman had 11, Kenny Hill and Ryan O’Connell scored nine apiece, senior Nate Landon punctuated Senior Night with six points and three blocks and Liam Spellman finished with a game-high 14 rebounds.

Luke Leonard had 17 points to lead East Lyme (13-6) and Nate Diaz had 14.

It was Diaz’s fourth 3-pointer of the night that gave East Lyme a 35-34 lead midway through the third period. East Lyme began the second half on a 12-4 run that prompted Bassett’s fateful timeout. He was tired of watching Diaz rain 3s on his team.

“Nate Diaz is a heck of a shooter,” Bassett said. “We know we have to get him off his spot. Dylan (Eckhart) did a nice job on him and then we used Payton, who is six inches taller, on him. I told my guys to take a little more pride in their defense instead of arguing with each other and blaming each other.”

The 35-34 lead crumbled quickly.

“You take a breath and Waterford goes on a 10-0 run in a minute and a half,” Bernardi said. “It’s a four-point game, six-point game and you look up and it’s 16. It’s tough, They’re good.”

The Lancers can win their fourth straight ECC Division II title Friday night at Fitch. They’re also closing in on a first-round bye in the state Division II Tournament. Perhaps they also learned something about sense of purpose Wednesday night.

“We talk about rivalries. I don’t care who’s in an East Lyme jersey or a Waterford jersey. It’s going to be a tough game,” Bassett said. “East Lyme has had to reinvent itself and they’re doing great. That’s not a team I would want to see in the state playoffs. All their guys are working together and they came with a sense of urgency. We need that same sense of urgency.”

Bernardi said, “We competed, but that’s not good enough. We expected to win this game and we had opportunities to do it. We let them hang around in the first half. Too many turnovers and missed layups. When Waterford got a chance to put the game away, they did. That was the difference.”

m.dimauro@theday.com