Seven days on from their Heineken Cup triumph, the European kingpins eventually ran out of steam as their quest for an unprecedented double came unhinged at Thomond Park.
Outscored three tries to none, Leinster appeared to be out on their feet during the final quarter and Schmidt agreed that it was one bridge too far for his tired troops.
"I think fatigue was obviously a factor," said Schmidt.
"We made a few changes because guys were out on their feet. That was something which we planned for, and felt was probably going to happen.
"To be honest, I kind of felt that Munster needed it more than we wanted it. They showed a lot of character, and that made it difficult for us to really keep our tempo, and play the game that we wanted to play.
"Even when we did have a little bit of momentum, we didn't quite have the sharpness that has allowed us to become successful so far."
The view from the Munster camp, by contrast, was one of complete satisfaction.
Having gone six games without scoring a try against Leinster, the men in red redressed the balance with three touchdowns en route to a thoroughly deserved victory. Wingers Doug Howlett and Keith Earls scored a try apiece whilst a late penalty try put the icing on the cake for the home side. Ronan O'Gara converted twice.
Leinster could only manage three penalties from the boot of Jonathan Sexton.
Munster coach Tony McGahan was effusive in his praise of the players, and also paid tribute to the Munster fans who finally have something to boast about.
"They can walk around with a smile on their faces, knowing that we have done something very important in the context of the Magners League season," he remarked.
The province's captain Paul O'Connell, meanwhile, said the whole occasion was testament to the rude health of the game in Ireland at present.
"I think today was a very good thing for Irish rugby," he said.
"Leinster and Munster have always made each other better, and we have made the Irish team better by driving on standards," he said.
"Both sides have a lot of leadership, and no little skill. People talk about this being a good era for Ireland, and when you look at some of the young players coming through, you would be very confident for the future."
Scorers: Munster: Tries: Howlett, Earls, penalty. Cons: O'Gara 2. Leinster: Pens: J Sexton 3
Munster: Jones; Howlett, Barnes, Mafi, Earls; O'Gara, Murray; Horan, Varley, J Hayes, D O'Callaghan, O'Connell, D Ryan, Wallace, Coughlan. Replacements: Warwick for Jones (75), du Preez for Horan (55), Leamy for D O'Callaghan (67).Leinster: Nacewa; Horgan, O'Driscoll, McFadden, Fitzgerald; J Sexton, Reddan; Van der Merwe, Strauss, Ross, Cullen, Hines, O'Brien, Jennings, Heaslip. Replacements: O'Donohoe for Reddan (76), McLaughlin for van der Merwe (58), Wright for Ross (69), Healy for O'Brien (58), Dundon for Jennings (69).
Referee: N Owens (Wales). Attendance: 26,100.