Thompson — Closing in on Eastern Connecticut Conference Open golf championship medalist honors, Killingly senior Ethan Lackner felt the heat.

And not just from high 80 degree temperatures that baked golfers at Quinnatisset Country Club.

East Lyme sophomore Sebby DeCosta, one of Lackner’s playing partners, kept the pressure on right until the final few holes.

Showing poise and persistence, Lackner drained a pair of roughly 8-foot birdie putts on the No. 18 and No. 1 holes — it was a shotgun start — and then sealed the win with a par on No. 2, finishing with an even par 72.

“That was the best round of my life,” Lackner said. “It feels good with all the work that I put in. It feels surreal right now.”

Killingly also won the team title for the eighth time in the last nine tournaments — and third straight — by placing four golfers in the top seven.

“It was a great day, for sure,” Killingly coach Kevin Marcoux said. “We have five really good players and anybody can medal at any time.”

With scores being posted in real time on the CIAC golf app, golfers and coaches knew exactly where things stood.

So it was no secret to Lackner and DeCosta that they were deadlocked with three holes to go.

“I was waiting for him to finally miss a putt, but he just kept on making them,” Lackner said. “When I made that double (bogey) on 16, I definitely felt the pressure because I went bogey before that. I knew the next hole was big for me to just get back on track and get my confidence going.”

Lackner, who plays at the No. 3 position for Killingly, rang up a par on No. 17 and went on to win. He topped his previous best finish of third in the ECC Open.

“Ethan certainly responded,” Marcoux said. “They were tied at one point and they were both under par at one point. They went back and forth and Ethan just separated himself. It was great to see.”

DeCosta felt good about his finish as well. He shot a 75 and ended up tying for second with Killingly senior Matthew Card, whose teammate Harrison Giambattista took fourth at 76 (Woodstock’s Davis Simpson rounded out the top five with a 77).

“It was intense,” DeCosta said of his first ECC tournament. “(Ethan) played really well. Props to him. I played the best I could. It was so nerve-racking, especially the first few holes. We started on the par 3 (third hole). It’s over water. I hooked my tee shot into a bunker, but I got up and made like a 30-footer for par. I gained some confidence after that.”

DeCosta joined the golf team after playing baseball as a freshman.

“I was pumped that he was going to be playing,” coach Rudy Bagos said. “I knew he could play. This is what our team needed. And the good thing is they’re all sophomores, so we can only get better.”

Killingly ran away with the team title, scoring 303 points to beat runner-up East Lyme by 30 strokes. Wheeler continued its breakout season by taking third (343) despite being without its No. 1 golfer, Kieran Boscoe who recently suffered a knee injury playing soccer.

Junior Cameron Conway led the Lions, finishing ninth with an 82. They finished the regular season with a program-best 17-1 record and posted their lowest score since the team started in 1977.

“I’m ecstatic for next year because they’re all juniors,” coach Carl Weber said. “We struggled in this tournament not knowing the course. It’s the first time my guys played with players of Killingly’s caliber. Maybe that will help us in the state tournament this year and next year moving forward.”

Killingly will be a serious threat to challenge for the Division II state on Tuesday at Fairview Farms in Harwinton.

It will be Marcoux’s final match as head coach of a program that he’s taken to great heights. He’s accepted a new job as the East Lyme athletic director.

“Tuesday is a big day,” Marcoux said.

g.keefe@theday.com