Groton — Tied for the lead with a few holes to play, Brad Adamonis battled a case of the nerves in the 41st Connecticut Senior Open.

“I didn’t have good nutrition this morning and I didn’t know what was going on, but I was really nervous,” Adamonis said.

While competing against co-leader Frank Bensel, Adamonis leaned on his tournament experience gained from his PGA Tour days in Tuesday’s final round at Shennecossett Golf Course.

Back in 2008, Adamonis reached a playoff in the John Deere Classic before falling to Kenny Perry and finishing as a runner-up. He also played in the Travelers Championship four times and before that one Greater Hartford Open, placing as high as a tie for sixth.

Showing poise under pressure, Adamonis, 50, broke the tie and captured the Connecticut Senior Open in his first appearance by sinking a three-foot birdie putt on the 18th hole. He finished the 36-hole event at 5-under 137 (68-69).

“It just tried to go off the experience that I had and tried to hit one shot at a time,” Adamonis said. “I wasn’t really hitting the ball the best, but I was scrambling well and putting well.

“As my father would say, who passed away, that’s the great equalizer, if you can make the putts. So I putted well and I scrambled well.”

It took some good fortune for Adamonis, who grew up in Cumberland, R.I., before moving to Florida, to get a spot in the tournament.

On the waiting list, Adamonis showed up to the course at 6:30 a.m. on Monday, waited out the rain, and officially found out at about 12:30 p.m. that he would be in the field.

“Not too many people root for rain,” Adamonis said. “Without the rain, I probably wouldn’t have been in the tournament, so I was pretty lucky. I was like the last alternate. I figured if it was raining out that I’d just show up and maybe I could get in.”

Adamonis, who played Shennecossett on Saturday for the first time, stood in a tie for second place at 2-under after Monday’s rain soaked first round. He joined East Lyme’s Bill Hermanson and Bensel, who led by one stroke after Monday’s first round, in the final group on Tuesday.

After Hermanson struggled on the front nine and fell out of contention, Adamonis and Bensel battled for control of the lead.

Bensel held a one-shot edge heading into the 15th. But he settled for bogey and Adamonis tied the match with a tap-in par on the par 3 hole.

Both golfers parred the 16th and 17th holes, setting up a dramatic finish.

When Bensel’s second shot on the par 5 18th landed on the green, took a bounce and ended up in the backside bunker, Adamonis was in the driver’s seat.

“He had a tough shot and I just wanted to get it on the green,” said Adamonis, who lives in Ponte Vedra, Fla.

Adamonis did find the green, leaving about 35 feet to the pin. He hit his third shot to within three feet and then drained the birdie putt to close out the match.

Bensel, who’s from Jupiter, Fla., finished at 4-under 138 (67-71).

“It was great,” Bensel said of the match. “Brad is a really good player and he played well.”

Dave Jones of Norwich won low amateur honors for the fifth time and tied for fourth place overall at 1-under 141 (69-72).

“It was really fun,” Jones said. “I really look forward to playing this tournament, it’s one of my favorite ones that we have all year.”

Standing at 2-under with five holes, Jones was in the hunt for the overall title but three-putted No. 14 and No. 15, missed a five-footer for birdie on 16 and missed a short putt for eagle on 18.

“You have to make those if you want to win,” Jones said.

Hermanson, who started the second round tied for second, ended up tied for 13th at 2-over 144 (68-76) after shooting five over par on Tuesday.

“I became very familiar with the bunkers,” Hermanson said. “And every time I was in it, I was up against the lip. I couldn’t really do much. But it was good to play with those guys and it’s always fun to play here.”

g.keefe@theday.com