Munster did get a try early in the second half that looked like it might kickstart a revival, but the error-littered nature of their display put paid to that possibility with Benetton Treviso taking full advantage.
The province's second successive away defeat has dented their RaboDirect PRO12 play-off hopes. They remain in sixth place with the Ospreys, in fourth, six points above them.
The aforementioned errors started right from Ian Keatley's kick-off when the normally ultra-safe James Coughlan knocked on, although he was caught unawares.
Less than three minutes had elapsed when Ludovico Nitoglia was dotting down under the Munster posts, Brendan Williams breaching slipshod defence to set the move in motion.
And despite playing into a stiff breeze, Treviso enjoyed territorial advantage and extended their lead in the 99th minute again off turnover ball with openside flanker Filippo Giusti getting over off a maul.
Keatley got Munster on the board with a penalty from the 10-metre line four minutes later but Rob Penney's men failed to use this as a springboard.
Instead, Gideon la Grange finished off the Italians' third try closing in on half-time. He dotted down after Denis Hurley failed to deal with a clever cross-field kick from Alberto di Bernardo.
The conversion followed from di Bernardo who also landed an easy penalty just before the break, giving Franco Smith's charges a clear 19-point advantage.
Munster had been the authors of their own downfall, getting turned over when attacking inside the Treviso 22 and Felix Jones was then caught in possession for the penalty award.
A little more cuteness when they broke free and Treviso could have had the bonus point try in the bag by referee Neil Paterson's half-time whistle.
The scrum was one area Munster got right and it led to their try in the 49th minute with stand-in referee Stefano Traversi, who had replaced hamstring injury victim Paterson, losing patience after the under pressure Italian scrum buckled yet again.
He also saw fit to give Treviso hooker Giovanni Maistri his marching orders, and Munster's resulting penalty try was comfortably converted by Keatley.
However, the men in red were unable to fully take advantage of the sin-binning. Treviso drew strength from Christian Loamanu's impressive display at number 8 where he stood in for Italian international Manoa Vosawai.
Munster could count themselves a tad unfortunate that a pass which put flanker Paddy Butler clear with the try-line at his mercy was deemed forward.
Ultimately it was incidents like that plus a plethora of unforced errors that sealed their fate. With Butler's back row colleague Tommy O'Donnell having just entered the sin-bin, defence again proved the province's Achillies heel in the 61st minute.
Treviso got over for their fourth try - something they had only done once before in this season's league - when lively scrum half Fabio Semenzato scampered away down the standside touchline.
The icing on the cake for the home supporters came two minutes from time. Winger Giulio Toniolatti slipped through a couple of tackles on the far side to score the fifth try which di Bernardo converted.
Giving his reaction afterwards, the province's head coach Rob Penney said: "I expected our boys to show more courage and fortitude. Some players need to take a long hard look at themselves after that.
"We were soft, we lacked courage, Treviso ripped into us and got the deserved outcome. Without taking away from them, that was definitely our most disappointing performance of the season."
The New Zealander added: "We’re not out of it (reaching the play-offs), but it means we need to have some great performances from here on in, plus were are relying on other teams to succumb, which isn’t ideal.
"It’s going to be a test of mental fortitude and resilience now, and all the other words you throw out when the sun goes behind a big black cloud.
"We’re in a professional sporting environment and guys need to make sure they are in the right mental place to front up again. If they don’t, they won’t survive in the game."