Munster ended their run of three successive cup final defeats in emphatic style as they ensured the Celtic League trophy remained in Ireland.
Their 20 point victory meant four defeats in a row for the Welsh All Blacks at the home of Welsh rugby and left the game in Wales staring with jealous eyes at the success of the Irish.
Even the loss of influential goal-kicker Ronan O'Gara before the half-hour mark couldn't stop Munster's charge to the title they were desperate to win.
O'Gara was helped from the field in the first half after he was caught at a ruck. His injury perfectly highlighted the difference in the two sides.
He was replaced by British Lions tourist Rob Henderson, who scored a superb second-half try. When Neath lost experienced hooker Barry Williams with a broken jaw, Lyn Jones had to call on Under-21 player Adam Matthews.
Ironically, Matthews was the first player Henderson beat on his way to the wonder try, although the youngster did show why Neath hold him in such high regard.
The injury is a blow for Williams, who was being mentioned as a possible replacement for injured Llanelli hooker Robin McBryde in Wales coach Steve Hansen's Six Nations squad on Monday.
It wasn't all doom and gloom for Lyn Jones, with fullback Adrian Durston showing glimpses of brilliance and impressive young props Adam Jones and Duncan Jones adding to their growing reputations.
It took O'Gara only two minutes to open the scoring in front of 30,000 fans - converting a penalty goal after a 30m surge from fullback Jeremy Staunton.
The All Blacks had their moments in the opening spell - especially when fullback Adrian Durston jinked his way through several tackles - but went further behind when O'Gara punished a swinging arm from Neath centre James Storey.
Jarvis halved the deficit when visiting flanker Alan Quinlan infringed at a ruck straight out in front of his posts, but Neath fans had little time to admire the scoreboard, with O'Gara slotting his third penalty goal in the next minute.
In the same incident, Neath's British Lions hooker Barry Williams was helped from the field with a broken jaw and things were looking bleak for the Welsh All Blacks.
O'Gara twisted the knife with a 47m penalty goal, but it was to be one of his last acts of the game. The Ireland international found himself on the wrong end of Sinkinson's right boot and limped off in the 25th minute to be replaced by fellow British Lions tourist Henderson.
Neath seemed inspired by the loss of such a dangerous opponent and Jarvis was tackled inches from the line after a silky run from Storey.
Munster were penalised for infringing at the ruck and were lucky not to earn a yellow card. Neath captain Gareth Llewellyn opted for the lineout but the Irishmen kept them out.
Jarvis ensured Neath didn't leave the Munster quarter without reward, however, with a well-taken dropped goal to reduce the deficit to six points.
But then came the moment that ruined Neath's fightback. As stewards were tackling a streaker in the Neath quarter, a Jarvis kick through was charged down and ricocheted into the arms of man of the match Quinlan, who raced 45m to score under the posts.
Staunton added the extras and he and Jarvis swapped penalty goals to give Munster a 22-9 lead at the break.
Jarvis slotted his third penalty goal moments after the restart, but Munster enjoyed a lengthy period on attack.
Makeshift fly-half Jason Holland, who played in that position in his native New Zealand, gave his side the territory when a speculative kick bounced off the head of unfortunate Neath winger Gareth Morris and rolled out inches from the corner flag.
From the lineout, Munster moved the ball to the centre of the field before the pack drove prop Marcus Horan over the line under the posts. Staunton's conversion took the score to 29-12 and the match was over as a contest.
Henderson - in only his second match since injuring a bicep in October - sealed matters with a superb try in the 56th minute. He jinked past two defenders before diving over in the corner in Shane Williams' tackle.
Neath decided if they couldn't win the war, they'd win a battle or two, with Storey flattening Peter Stringer after the Munster scrum-half trampled on Shane Williams at a ruck. Referee Chris White, who had a good game with the whistle, showed both players a yellow card.
Staunton, who was many fans' man of the match, kicked his second penalty goal in the 79th minute but Neath had the final say.
Hard-working prop Adam Jones barged his way over in the final act of the game, but it was of little consolation for Lyn Jones, who went into the match demanding an improvement on his side's 35-19 loss to Munster in October.
Jones is an outspoken supporter of the WRU's plans to regionalise Welsh rugby into four teams, but at least he doesn't have to waste his breath arguing the point any more. He just has to show any doubters a video of today's game.