Rob Penney's final home game at Thomond Park ended in defeat as Munster fell to a 19-17 defeat against a fired-up second string Ulster side.
The departing head coach watched his charges lose this tight inter-provincial affair, although a victory would not have mattered anyway given that Glasgow sealed second place by demolishing Zebre in a bonus point win.
An Ian Keatley penalty and Duncan Williams' converted try put Munster in the ascendancy, before Ulster's Michael Heaney crossed with James McKinney's conversion and penalty levelling matters at 10-10 at the interval.
Sean Dougall's seven-pointer moved the hosts back in front, but nine more points from McKinney's reliable boot proved decisive as Ulster recorded their first season's double over Munster since 2009.
Munster are away to in-form Glasgow in next week's play-offs and they will have to raise their game significantly from this showing.
Ulster, who finished the regular RaboDirect PRO12 season in fourth, will have renewed hope for their own semi-final trip to winners Leinster.
With both sides having already secured their play-off spots, there were wholesale changes for this round 22 date.
Ulster head coach Mark Anscombe made 12 changes to the team that narrowly lost to Leinster, while Penney brought in 10 new faces to the side that thumped Edinburgh 55-12.
Despite a sloppy opening, the hosts took the lead in the 11th minute when Keatley successfully kicked a penalty after an infringement.
And soon after, the game's first try arrived from a superb interchange of passing between James Downey and James Coughlan which sent scrum half Williams over in the corner.
Although Keatley brilliantly converted from the touchline to put Munster 10-0 up, Ulster hit back as the home defence were caught napping following a turnover and Heaney crossed to reduce the deficit.
The try was given following consultation over the receiving pass from Michael Allen and McKinney added the extras to make it 10-7.
On 36 minutes, Ulster tied a scrappy and error-ridden match when McKinney landed a penalty from just inside the Munster half.
McKinney then kicked the visitors ahead after the restart with another penalty, but Munster responded immediately with seven points.
Dougall pounced on Keatley's grubber kick through and the latter nailed his third consecutive kick to regain the lead at 17-13.
However, McKinney grabbed his fourth and fifth successive kicks to put the Ulstermen 19-17 in front with 15 minutes to go.
Despite an increased effort, Munster were unable to claw victory from defeat as replacement JJ Hanrahan missed a last minute drop goal and injury-time penalty attempt from halfway.
Having lost to Glasgow recently, it was Munster's first time to taste back-to-back league defeats at Thomond Park since April 2010.