Ian Keatley's impeccable kicking display inspired leaders Munster to a hard-earned victory at Cardiff Blues.
The Irish fly-half kicked six out of six penalties to extend Munster's record winning run to 14 games - before Keatley was sin-binned late on.
Alex Cuthbert, who had a first-half try ruled out, gave the Blues hope as the young wing finishing off a flowing break created by giant lock Paul Tito.
Cuthbert thought he may have won it in added time but the score was ruled out.
Referee David Wilkinson had adjudged that Dan Fish's scoring pass to Cuthbert was forward as the dominant Blues, who only had a bonus point to show for their efforts, squandered a glorious chance to make their territory and possession count.
The Irish province showed why they are defending league champions as they ground out a fourth straight win at the start of this new Pro 12 campaign, despite barely making it into the Blues 22.
Fly-half Ceri Sweeney kicked eight of the Blues points but, as his opposite number enjoyed a 100 percent record, the former Wales international missed kick two presentable three-point chances early on and they proved costly.
The Blues despair began in the 13th minute when video referee Gareth Simmonds ruled Cuthbert put a foot in touch as he went through to score.
Denis Hurley's desperate tackle did the job for Munster before the officials decided that prop Sam Hobbs had been stopped short of the line.
The hosts' pressure did finally yield points after 19 minutes as tighthead Scott Andrews won a scrum penalty which Sweeney knocked over to tie Keatley's earlier kick.
But Keatley replied by sweetly kicking three penalties to hand Munster a 12-3 interval lead.
Cardiff finally found a way of breaching the Munster defence early in the second-half as a simple pop pass from captain Tito sent Cuthbert racing through 40 yards out.
And the Wales Sevens international showed good pace to round Duncan Williams to cross for his second try in successive games before Sweeney added the conversion from out wide.
Cuthbert's score was the first try Munster had conceded in this competition since last season's semi-final win over the Ospreys.
But the visitors quickly responded with Keatley's fifth penalty.
And Cardiff's lack of discipline proved costly as they gave Keatley another sight of the posts just before the hour, which the fly-half gratefully accepted.
Another Cuthbert run earned the Blues more points when he was hauled down just short of the line after a half-break from Sweeney.
Desperate Munster defenders infringed and Sweeney kicked the simple penalty before Cuthbert was denied again late on in dramatic fashion.
Cardiff Blues: Fish, Cuthbert, Evans, Hewitt, Mustoe, Sweeney, Rees, Hobbs, Thomas, Andrews, Tito, D. Jones, Paterson, Molitika, Rush.
Replacements: Laulala for Hewitt (52), L. Jones for Rees (52), Trevett for Hobbs (68), Harford for Andrews (68), Down for Tito (60), Young for Paterson (72). Not Used: Patchell, R. Williams.
Munster: Murphy, Howlett, Barnes, Mafi, D. Hurley, Keatley, Williams, du Preez, Sherry, Archer, Holland, O'Driscoll, O'Mahony, O'Donnell, Coughlan.
Replacements: Gleeson for Barnes (66), Stringer for Williams (50), J. Ryan for du Preez (72), Fogarty for Sherry (52), Foley for O'Mahony (55), Ronan for Coughlan (28). Not Used: Deasy, Hayes.
Referee: David Wilkinson (IRFU)
Assistant Referees: David Jones, Huw Griffiths (WRU)
Citing Commissioner: Jeff Mark (WRU)
TMO: Gareth Simmonds (WRU)