Munster were made to struggle to keep their unbeaten Heineken Cup record at Thomond Park by a feisty Harlequins.
HEINEKEN CUP POOL 4
Munster (15) 15
Tries: Horgan, Leamy
Harlequins (3) 9
Pens: Staunton 3
In a abysmal conditions, Quins looked to be heading for certain defeat after Anthony Horgan and Denis Leamy scored first half tries.
But a third penalty by Jeremy Staunton kept the game on the boil right until the end of an absorbing contest.
In the end Munster hung on with Ronan O'Gara having earlier added a conversion and an angled penalty.
With rain pouring down over the Limerick venue it was Harlequins who made the early running with Staunton sliding over a penalty.
In the 10th minute, both sides were reduced to 14 men when a rather pedantic Hugh Watkins handed out yellow cards to respective props Maurice Fitzgerald and Marcus Hogan after the scrum collapsed.
Munster immediately gained control when a quick penalty by Anthony Foley saw the ball spin out to Christian Cullen whose slip pass allowed O'Gara to put Anthony Horgan scurrying into the corner.
There was worse for Quins when four minutes after Staunton became the third player to be binned after a deliberate knock-on, Munster scored their second try.
The excellent Jim Williams took advantage of a turnover and his charge and off-load put fellow flanker in at the corner. O'Gara converted with a great touchline conversion.
Even when they were back to a full compliment, Quins found Munster's power up front and the continuity play extremely hard to handle.
But despite their possession, all Munster had to show at half-time was another penalty by O'Gara who gave them a 15-3 cushion.
Harlequins started the second half in a more positive mood and Staunton slipped over his second penalty to reduce the arrears.
Even when replacement hooker Ace Tiatia was yellow-carded for a high tackle on Horgan, Munster still could not find the cohesion against the 14 men.
Instead, it was Quins who clawed back some of the leeway with Staunton rifling over his third penalty with 13 minutes remaining.
Munster were never to find their rhythm again and instead had to hang on grimly to keep Quins out.
Munster: Cullen, Lawlor, Kelly, Henderson, Horgan, O'Gara,
Stringer, M. Horan, F. Sheahan, J. Hayes, T. Hogan, O'Connell,
Williams, Leamy, Foley.
Replacements: Flannery, McIlwham, Bowman, Quinlan, Wallace,
Harlequins: Duffy, Harder, Greenwood, James, Keogh, Staunton,
So'oialo, Jones, Fuga, Fitzgerald, Winters, Miall, Easter, Vos,
Replacements: Tiatia, Worsley, Palepoi, Sherriff, Dunne, Deane,
Referee: Hugh Watkins (Wales)