Tries from Lucas Amorosino and Manoa Vasowai looked to have given Cardiff an unlikely victory, but Butler scored Munster's only try of the game in the dying moments.

JJ Hanrahan was flawless with the boot for the visitors with seven from seven, and has now managed 22 successful kicks in a row against the Blues.

Hanrahan and Rhys Patchell traded two penalties each inside the opening 15 minutes, but Cardiff were not looking like a side without a win in five in the GUINNESS PRO12.

Despite playing exciting rugby, Cardiff concended two more soft penalties as they tried to play out of their own half.

Hanrahan made no mistake to give Munster a 12-6 lead, as Cardiff were put under pressure with the Irish province clinical at the breakdown.

A great turnover by Josh Navidi won the Blues a penalty right in front of the posts on 23 minutes, and Patchell kept them in touch.

But Hanrahan was relentless with the boot, and hit his 20th consecutive kick against Cardiff on 32 minutes to restore the six-point margin.

Cardiff gained some momentum with breaks from Richard Smith and Gavin Evans, and Amorosino's debut try came with a superb finish in the left corner thanks to Patchell's well-timed offload.

Patchell could not convert from the sideline, but Cardiff grew in confidence and were firmly on top going into the final few minutes of the half.

Munster would not lie down however and, after regaining possession, a brilliant break from Robin Copeland allowed the visitors to build pressure on Cardiff's line.

And while Rory Scannell wasted a huge chance for a try - opting to go alone with support outside - Hanrahan kicked his sixth penalty of the half.

Smith broke as the clock ticked into the red to earn the Blues a very late penalty, but Patchell missed his second in a row to give Munster an 18-14 lead at the break.

Cardiff came flying out of the traps at the start of the second half, continuing to play a scintillating brand of rugby but were dealt a blow on 53 minutes as Patchell limped off.

But Cardiff maintained their pressure on the Munster line, and were perhaps unlucky not to be awarded a penalty try after a series of scrums five metres out.

But their territory finally paid off on 62 minutes when Manoa Vosawai crashed over from yet another scrum with a superb display of power as Munster's defence were worn down, replacement Thomas Davies adding the extras.

Munster needed a response and Hanrahan's boot brought them level at 21-21 on 68 minutes with the Blues conceding yet another disappointing penalty in their own half.

Adam Jones' audacious attempt at a drop-goal fell just short when Cardiff had the advantage, but Davies was clinical again with the resulting penalty to give the Blues the lead with just six minutes left on the clock.

An immediate lack of discipline again from the hosts allowed Munster to put the ball into the corner with Johnny Holland on for Hanrahan, but CJ Stander knocked-on to miss a huge opportunity.

Munster's belief was not gone and Stander's carry allowed Butler to break through for the match-winning try, and Holland judged the wind brilliantly to convert and make the margin four points with three minutes remaining.

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