"I'm absolutely thrilled. Firstly, it's great to get the win, but there's probably a couple of things we have to work on next week," said the Leinster flyer.
"The first half performance probably wasn't the best, while the second half was better. Joe (Schmidt) had a few words at half-time and I think we upped our performance in the second half. Thankfully I was at the end of a couple of good moves to get in in the corner.
"There is a lot of competition. We have a really strong squad, with a lot of strength in depth. Not great for me, but especially in the back-three, there is a lot of talent and strength in depth there so I've got to build on this performance and try to put my hand up for a spot."
With his provincial colleague Jack McGrath also making his first senior appearance for Ireland, it was a special night for the pair with Kearney eagerly awaiting his introduction before getting the signal to go on midway through the second period.
"I was itching to get on from the start. I found out after 55 minutes that I was coming on in five minutes, so I had five minutes to get my head around it and get ready for it," revealed the 24-year-old.
"I think it is probably similar enough to any other game. I like to approach games like they are all the same. Sometimes when you are not in the starting fifteen, you are not as nervous, but I think when the game starts you get a bit more nervous leading up to it. You focus on getting on and what you need to do."
Kearney was set up his older brother Rob for the first of his two tries and Ireland head coach Schmidt joked afterwards that a better pass from the elder Kearney could have seen the debutant score a hat-trick.
"I haven't seen it. Was it a bad pass?", enquired Dave of the missed opportunity, before speaking about being put in for his first senior try by his brother in the 66th minute.
"I haven't seen it yet. I'm not sure if he could have went himself, but I think he saw the younger bro outside him and it's an early Christmas present I suppose!
"He used to do it when we were younger in the back garden with no opposition, so I suppose you could say we have done it before.
"It's brilliant (to play together at this level). We have played a lot before with Leinster, so it is not too dissimilar. It's just putting on that green jersey, which makes it that little bit special."
Up next for Ireland is a mouth-watering clash with the Wallabies who, having trailed Italy 10-0 after 12 minutes, ended up scoring seven tries to post a 50-20 victory in Rome.
Kearney hopes his performance will have put his name in contention for a start, but knows that the mistakes that went unpunished against Samoa could prove costly against Australia.
"Australia put 50 points on Italy. I think we are going to up our performance again next week. A couple of loose passes and offloads and probably not strong enough in the contact - we let a couple of balls slip, I think. Next week if we do that against Australia, we will probably be punished."