Tries from wingers Doug Howlett and Keith Earls, allied to a late penalty try, helped Munster bring the Heineken Cup winners back down to earth.
Tony McGahan called for attitude and intensity from Munster and he got it in spades as the province lifted the league title for the second time in three seasons at Thomond Park.
Table-toppers since round two of the competition, Paul O'Connell and his team-mates outfought a tired-looking Leinster side who could only muster three penalties from Jonathan Sexton.
Fresh from a weekend off, Munster fielded an unchanged starting line-up from their 18-11 semi-final defeat of the Ospreys.
Gordon D'Arcy's ankle injury saw Fergus McFadden join Brian O'Driscoll in the centre for Leinster, who reintroduced Heinke van der Merwe and Shane Jennings in the pack.
It was a win apiece earlier in the campaign - Leinster were 13-9 winners at the Aviva Stadium and a Ronan O'Gara-inspired Munster claimed a 24-23 triumph in Limerick last month - and there was a typically bruising opening to the grand final.
Sexton miscued a long-range penalty with the wind behind him, six minutes in, and although Leinster won a series of early turnovers Munster were showing much more in attack.
Twice Howlett was put into space on the right and on the third occasion, Lifeimi Mafi danced away from Eoin Reddan to send the former All Black over in the corner for the opening try.
O'Gara read the wind superbly to stab the conversion over, rewarding his forwards for an energetic start. O'Connell and man of the match David Wallace were both to the fore, the latter keen to impress in his 200th outing for Munster.
The turnover rate was high as the sides scrapped for every ball. Munster exerted more control through O'Gara and Conor Murray, with Leinster having to attack from deep.
One such counter-attack led to a cynical shoulder charge by Marcus Horan on O'Driscoll which was missed by the match officials. A subsequent scrum infringement saw Sexton split the posts from a central position.
Closing in on half-time, Murray sparked a break that might have led to a try and O'Gara's hurried drop goal attempt lacked conviction.
A sparkling run and pass from O'Driscoll got Leinster immediately into scoring range after the break. The visitors' forwards battered away at Munster's defensive line until Donncha O'Callaghan saw yellow for not rolling away in front of his posts.
Sexton took the three points on offer and Munster staved off Leinster's next assault on their line - Richardt Strauss and McFadden, tackled brilliantly by Wallace and James Coughlan, were both thwarted.
A looping pass from Sexton was mishandled by McFadden as Munster were caught for numbers out wide, but the Leinster out-half was successful with a right-sided penalty soon after for a 9-7 lead.
With just 20 minutes remaining it was anybody's game. Munster then barged back to within metres of the Leinster line, a thunderous tackle from Luke Fitzgerald knocking Howlett to the ground just when a try looked on.
But Munster turned the screw when O'Gara lofted a cross-field kick over to Earls, who avoided Isa Nacewa's initial challenge and scored despite a despairing tackle from Shane Horgan.
O'Gara was narrowly wide with the conversion and watched his 48-metre penalty miss the target, with nine minutes remaining.
However, Leinster's hopes were extinguished by the concession of a third try. One of their strengths all season, the scrum, let them down as Munster drove them back at an alarming rate on two occasions and referee Nigel Owens signalled for a penalty try.
O'Gara's conversion took the lead to 10 points and Leinster were even denied a meaningless late try as both Kevin McLaughlin and Nathan Hines were stopped by Munster's dogged defence.
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
$29.99
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.