Clontarf lost their grip on a 21-13 half-time advantage and needed a late Joey Carbery penalty to draw 27-27 with hosts Young Munster at Tom Clifford Park.
Despite missing out on a fourth straight victory, Clontarf remain top of the Division 1A standings – a point clear of Old Belvedere. Missed tackles from Young Munster allowed the visitors through for three first half tries, including a sixth try in four outings for Leinster winger Mick McGrath.
'Tarf conceded territory from the off in Greenfields and sharp South African scrum half Abrie Griesel, making his home league debut for Munsters, made them pay with a third minute try that Paul Downes converted.
However, the Cookies' bright start was broken up by a typically forceful run through the middle and try from that man McGrath. The conversion was clipped over by Downes' opposite number Joey Carbery.
The clinical edge that 'Tarf displayed in their three previous outings was evident when flanker Karl Moran rumbled over, punishing some poor defending from the hosts. Carbery added the extras for 14-7.
Munsters came back strongly with lock Sean Duggan's determined counter-rucking winning possession back in the visitors' 22, and it some last-ditch scrambling from the north Dubliners to avoid the concession of a close-in try.
Good work from the Munsters forwards won two kickable penalties which out-half Downes slotted through the uprights, but sandwiched in between was 'Tarf's third seven-pointer of the afternoon – loose tackling allowed young centre Conor O'Brien to crash through and add to his side's tally.
A bonus point seemed inevitable for Andy Wood's men at that stage, leading 21-13 at the interval. However, Munsters had other ideas, with their pack literally growing in stature with the introduction of some beefy replacements.
Clontarf were guilty of coughing up possession in vital areas of the pitch. Credit to Munsters, they seized the initiative with flanker Diarmaid Dee plunging over on the end of a rolling maul.
Downes' successful conversion was cancelled out by a Carbery penalty. Some of referee Stuart Gaffikin's decisions angered both sides, but fired-up Young Munster let their rugby do the talking for a terrific third try.
Two of their most promising backs, Ireland Sevens international Diarmaid McCarthy and Ireland Under-19 starlet David O'Mahony, made great ground in the build-up to their back-three colleague Darragh O'Neill's converted score, as 'Tarf were caught out down the blindside of a scrum.
Suddenly, Wood's charges were 27-24 behind and staring at their first defeat of the campaign. They were admirably patient, though, in working their way back into a scoring position.
A solid drive from the forwards earned them a penalty in front of the posts and Carbery's second three-pointer of the day was the final score of this entertaining encounter. Ireland Under-20 international Carbery has quickly become an important part of the Clontarf back-line since his summer move to UCD.
That levelling penalty took his 2015/16 league haul to 49 points, while despite missing out on the win, Young Munster will take great encouragement from this much-improved display, just seven days on from their 34-point hammering by UCD.
Referee: Stuart Gaffikin (IRFU)