After two defeats in succession, Young Munster bounced back to winning ways at Tom Clifford Park on Saturday afternoon.
Once again out-half Willie Staunton was their scorer-in-chief and he bagged a total of 15 points, starting with a a third minute penalty from almost the halfway line.
He doubled his tally with another good strke in the 11th minute, but Staunton's opposite number Darragh Fitzpatrick kept Blackrock in contention with a penalty for a ruck offence three minutes later.
Staunton then steadied the Young Munster ship with a drop goal following a lineout, and he raised a huge cheer from the home supporters when he landed a penalty from near the left touchline midway through the half.
On the stroke of half-time, Young Munster gained their only try of this Division 1A encounter. Staunton lofted a hgh kick which was fielded by Blackrock's Rob Keogh.
He, in turn, kicked back but the ball broke in midfield to Munsters centre Mike Kelliher and he gave the vital pass to winger Mark Doyle to make it 17-3 at the interval.
Another penalty by Staunton pushed the home side out to 20 points, leaving Blackrock with quite a mountain to climb.
When the Dubliners were awarded a kickable penalty they opted to kick to the corner. The lineout was duly won by Eric Miller's side, enabling the influential Fitzpatrick to nab a try which he also converted.
Young Munster had their loosehead prop Ger Flaherty sin-binned but the visitors could not capitalise and it was the Cookies who had the final say when replacement Shane Hassett, who is emigrating to Australia, got over for a try in what was his last game for the club.
Referee: John Carvill (IRFU)