Cardiff 25-22 Munster: A try by Cardiff wing Tal Selley deep into injury time thrilled a St David's Day crowd of 11,269 and took the Welsh team into second place in the Magners League table.
Munster appeared to have survived a late barrage until Wales squad winger Jamie Roberts burst through the middle and sent Selley under the posts.
The Blues had gambled with the selection of 20-year-old fly-half Rhys Jones, on loan from Sale Sharks, for his first start.
It could hardly have begun worse for the son of former Wales captain Kingsley.
After the home side claimed Munster's kick-off, his attempted clearance was charged down and the visitors reclaimed possession.
Jones' opposite number Paul Warwick coolly chipped the defence and full-back Shaun Payne won the chase to touch down unopposed after just 50 seconds. Warwick converted off the left-hand post.
The Blues - and Jones - regained their composure and began to show their undoubted ability.
Winger Roberts went on a rampaging run which ended with a penalty by Ben Blair.
Warwick and Jones were each wide with penalties, before a superb break by centre Jamie Robinson created a fine try for the Blues.
He was supported by Gareth Thomas before the ball was recycled and spread right for hooker Rhys Thomas to score.
Blair failed with the conversion, and Warwick was off target with a drop goal, before Munster's Australian fly-half put them back in front with a penalty which, like his earlier conversion, glanced in off an upright.
The visitors extended their lead early in the second half, prop Tony Buckley forcing his way over after good work by lock Paul O'Connell and scrum-half Peter Stringer, both staking their claim for a place in the Ireland line-up to face Wales next Saturday.
Munster were monopolising possession - some aimless Blues kicking contributed to that - and went further ahead when skipper O'Connell scored after some neat back play by Lifeimi Mafi and Doug Howlett. Warwick converted the try.
Blues coach Dai Young brought on a raft of replacements and Thomas burst down the middle for Roberts to go over wide on the right. Blair's conversion cut the gap to four points.
The last five minutes were played out deep in the Munster 22, but the Irish looked certain to hold out until Selley's dramatic late thrust.
Blair's conversion with the last kick of the game merely rubbed it in.