Victory over ASM Clermont Auvergne in Bordeaux on Sunday handed Leinster a third finals appearance in four years after plenty of pundits had predicted home country advantage would see the French outfit triumph at the Stade Chaban Delmas.
But reaching the tournament's Twickenham showpiece was far from straightforward and Leinster could have been heading home heartbroken had Clermont centre Wesley Fofana not dropped the ball over the line in the dying stages.
And while the bookmakers have Leinster as clear favourites for the final due to their outstanding recent record against their Irish rivals, Kearney knows Ulster will be no pushovers on the biggest stage of all.
"Ulster really deserve to be in the final. They've had a fantastic season and they've had some big wins along the way," said Kearney, who played in Leinster's 2009 Heineken Cup win but missed the 2011 final through injury.
"We're going to need to up our game if we want to beat them. We know we're in for a right battle.
"Ulster have had a fantastic season, credit where credit is due. They beat Clermont at home which isn't easy and they gave it a right go away from home. They're flying high and they're very confident at the moment.
"They were missing some key players when we played them (in the league) last week and those key players make a huge difference to their team. When they have those back for the final, it will be a completely different game and they'll be much tougher opposition.
"We were probably a little bit lucky at the end against Clermont - nine times out of 10 Fofana scores that try - but we'll take it when it's there.
"We had to dig really deep at the end and our forwards on the front line, I can't speak highly enough of them."
Kearney was named Heineken Man of the Match for his role in the 19-15 semi-final success on French soil, thanks in no small part to what he describes as a 'five-minute cameo' in which he played a vital part in Cian Healey's crucial converted try and knocked over a long-range drop goal.
"As the lads were saying inside the dressing room, a five-minute cameo and that's all I did in the whole game! I've tried enough drop goals and I've missed them so it's nice to finally see one go between the sticks.
"We haven't used the move (that led to Healey's try) since Christmas. It's something we knew we were going to score off - we just had that belief. The last game we used it was Cardiff Blues away at Christmas and we scored off it then.
"We knew that if we got any sort of a lead it was going to be difficult for them to get back down and get some field position because there was a stronger wind than it appeared."