Larin, 30, powered a header past Egil Selvik to score with his first touch as a Saints player right in front of the Northam End.
The Canadian international knew he just had to attack James Bree’s corner delivery, but was not entirely sure he had scored three minutes into his debut.
Larin, who arrived on loan from Mallorca on Monday, credited his teammates and Southampton’s staff for making his adjustment to the south coast so seamless.
“To be honest, I don’t think it could have gone much better. The guys, the team, and the staff have made me feel comfortable since I first came,” he told the Daily Echo.
Cyle Larin scored with his first Saints touch to beat Watford 1-0. (Image: Stuart Martin)
READ: Larin scores with first Saints touch to earn narrow victory over Watford
“They’ve helped me settle in. All of that plays a part in what we saw on the pitch. They’ve helped my family settle, which allowed me to focus on the football side.
“The guys have been great. They are a great group of guys who have made it easier for me to go onto the pitch and perform.
“When it came off of his [Bree’s] foot, I saw it come into a certain space on the pitch, and I just attacked it. To be honest, I didn’t know if it had gone in or not.
“But when I saw the ball hit the ground in the back of the net, I was happy to score, to see the celebrations. I’m over six feet, and I can score with my head and feet.
“The team puts in good service – that is what I’ve watched many times before I came here – when you have that service and chances, that’s the most important thing.”