The opening score came in the 8th minute, from the home side, after a jinking Shane Williams forced Munster to concede a penalty inside their own 22 and after James Hook had opted for the five metre line-out, the Welsh star broke Donncha Ryan's tackle to score on the right, his conversion putting Ospreys seven points up.
Ryan made amends minutes later when he took a pass from Tomas O'Leary - whose superb break left the Ospreys defence for dead - and cut inside to score a try that originated in a crunching tackle from Brian Carney just inside the Ospreys half. Carney was once again seen to good effect shortly after, when he managed to palm Hook's attempted touch-find from a penalty back into play to deny the Ospreys another five metre line-out.
Hook had an opportunity to add to his side's total with a 26th minute penalty from 40 metres wide on the right that fell short but he had an easier chance three minutes later and made no mistake.
Munster looked in trouble in the 34th minute when Andrew Bishop broke clear and sent Sonny Parker hurtling for what looked a certain try only for Anthony Horgan to rescue the situation with a marvellous covering tackle. However, in the next phase, Munster were penalised again but referee David Changleng reversed the award and Manning cleared to half-way.
Williams once again spread havoc in the Munster defence, they were penalised again, lost Donncha O'Callaghan to the sin-bin and Hook tapped over the kick to leave his side eight points up at the break (13-5).
Roared on by the Under 15s from Ul Bohemians, thirteen man Munster started the second half with a clean Ryan take from the restart and a good drive downfield but they were indeed fortunate when a clean Hook break left Munster's defence in tatters but he somehow managed to throw a forward pass to Parker certain try under the sticks.
Munster were under the cosh at this stage but lifted the siege with the return of O'Callaghan only to surrender good field position when they were penalised inside the Ospreys 22.
Declan Kidney sent on Ronan O'Gara and Marcus Horan in the 53rd minute and their arrival heralded Munster's best period, instigated by Alan Quinlan's superb break on the right and a forward drive on the left that was stopped just short.
Another penalty concession gave Ospreys the platform for their second try when Ryan Jones took the throw in at the back and dropped it down perfectly for replacement Justin Marshall to race through the line-out for an easy run in.
Hook added the extras (20-5) and really should have put Ospreys further ahead but he ignored three men outside with the tryline at their mercy. Ospreys were reduced to 14 for the closing minutes when replacement Barry Williams was yellow-carded and not only did Munster deny Ospreys their expected bonus point but they ended with a crossfield kick from O'Gara that was claimed by Carney for a try in the corner that O'Gara brilliantly converted.
And they might have had another when they fashioned a great injury time break out that involved Lifeimi Mafi, Quinlan and Anthony Foley that aw the game ending on the Ospreys line
Munster: M Lawlor, B Carney, B Murphy, L Mafi, A Horgan (K Earls 65 min); J Manning (R O'Gara 53 min)), T O'Leary; F Pucciariello (M Horan 53 min), F Sheahan (J Flannery 65 min), T Buckley; D O'Callaghan, D Ryan; A Quinlan, J O'Sullivan, A Foley capt.
Ospreys: S. Terblanche; J. Vaughton (N Walker 65 min), S. Parker, A. Bishop, S. Williams, J. Hook, J. Spice (J Marshall 60 min); P. James, H. Bennett (B Williams 60 min), C. Griffiths (A Jones 58 min), B. Cockbain, AW. Jones, A. Lloyd (J. Thomas 3 mins), R. Jones, S. Tandy (R Pugh 3 min).
Referee: David Changleng (SRU).