It has been a superb first international season for winger Dave who has taken to Test rugby like a duck to water, running in a brace of tries on his debut against Samoa in November and winning six successive caps since then.
The siblings from the Cooley Peninsula join a list of Championship-winning brothers that includes Scotland's Hastings (1990) and Leslies (1999), the Underwoods from England (1995) and France's Lievremonts (1998).
Speaking on TV3's 'Ireland AM' programme, Dave said of the closing stages against France: "It was pretty special and nerve-wracking at the same time. The last 10 minutes were obviously difficult to watch.
"Games are so tight in the Six Nations and I think teams never really go through the whole Championship without fighting out those really close games, those two-three pointer games."
His older brother Rob, who was part of the 2009 Grand Slam-winning side, also spoke of his relief when being interviewed on Newstalk's 'Lunchtime' show.
"There was a collective sigh of relief that we had won it. We played well throughout the whole tournament. Our destiny was in our own hands for most of the game. There was a real element of relief there," admitted the full-back.
The elder Kearney has been playing some of the best attacking rugby of his career in the green jersey this season, from his intercept try against the All Blacks to his more recent scores against Scotland and England.
Rob, who turns 28 next week, is confident that if this new-look Irish squad maintain a high work-rate and continue to improve, they can keep challenging for silverware as their player depth increases and the game-plan evolves.
Another obvious positive for them is the current coaching regime headed up by Joe Schmidt, which is seemingly getting the best out of the players - both the experienced internationals and newcomers like Dave Kearney and props Jack McGrath and Martin Moore.
"Just because we have won a Six Nations Championship, that doesn't automatically make us World Cup contenders. We need to continue growing and developing as a team. Provided we can do that, this team can do really good things," insisted Rob.
"You just have to look at Joe's record since he has come to Ireland. It's incredible - a couple of Heineken Cups, a PRO12 title and Amlin Challenge Cup, there's a Six Nations Championship there now.
"There is no doubting that he is a highly impressive coach. Whether there's many better than him in the world, it's very debatable. He will not allow us to lose the run of ourselves and he will make us better every single week. That's the key."
"We work really hard, both players and management, and that's especially been the case over the last eight weeks. You rarely have time to switch off and that's one of the things with Joe - it's always a really intense environment.
"He always keeps guys on their toes and I think that probably gets the best out of players. It really keeps players pushing for (starting) spots and keeps competition really high."
The 24-year-old winger has been rewarded for his consistent form, making his Six Nations debut against Scotland and holding onto the coveted number 11 jersey in the same manner that his Leinster team-mate Luke Fitzgerald did back in the 2009 Grand Slam season.
Kearney was actually on the cusp of his first Ireland cap two years when he was an unused replacement against Wales, but his patience and diligence were rewarded with that two-try salvo against Samoa and an impressive full debut against New Zealand.
The player himself, who lined out for the Emerging Ireland side in Georgia last summer, is determined to keep possession of his Test jersey as he looks to reach further heights in the coming months.
"Sport is pretty fickle. With the back-three there is a lot of competition. A lot of it is luck and timing," he suggested.
"When players do get injured - and it's the same for any player who is trying to get into a position - it opens an opportunity for other guys to get a chance, that's when you really need to take it.
"Some of the guys who aren't involved...it makes you perform and it keeps you on your toes."
Kearney picked up a knock during the 22-20 title-clinching win over France, but will be available for Leinster's mouth-watering derby clash with Munster next week.
"I got a bang on my hand, but it's nothing too serious. I had an X-ray yesterday (Monday) and it was perfect.
"We have the week off now and we're back in for Munster (next week). It's funny because it's the guys you've been playing with for the last eight weeks or so, and we're straight back in next week to beat the hell out of each other!"
For a few days at least, the Kearneys can bask in the glow of Championship glory and Rob spoke of his immense pride in winning the Six Nations with his younger brother as a team-mate.
"It's a really proud moment. Any time I take the field with Dave is really cool, and when we win a trophy together it's obviously that little bit sweeter," he said.