Peter O'Mahony's first-half try proved decisive as Munster ground out a 10-3 win over Saracens in Pool Four of the Heineken Champions Cup.
In the first of back-to-back clashes between the sides, a low-scoring encounter at Thomond Park ended in a seven-point win for the southern province to leave them second in Pool Four after three matches.
Despite earning a losing bonus point, this result leaves Saracens - the defending champions - third in the pool, with next weekend's clash between the sides in London now taking on an even greater significance.
With the visitors fielding a weakened line-up, Munster recalled a number of big names and played with the aid of a strong breeze at the Limerick ground in the first half.
JJ Hanrahan opened the scoring with a penalty and Munster thought they had their first try when Rory Scannell raced through, but it was ruled out for a forward pass.
Scannell, though, was heavily involved in Munster's first try soon after, when his pass to Keith Earls help set in motion the move that led to Peter O'Mahony crashing over for what proved to be the game's only try after half-an-hour.
This score - converted by Hanrahan - left Munster 10-0 up.
After an earlier effort came back off the post, Saracens opened their account with Ben Spencer slotting a penalty to leave his side 10-3 down at half-time.
Conditions contributed to a second-half in which neither side registered a score.
In heavy rain and strong wind, Munster battled well to hang on to their seven-point lead, with Saracens failing to apply any real pressure.
However, there was late drama when Munster's Arno Botha was red-carded for what was deemed dangerous play. Botha was adjudged to have led with his arm and was sent off.
Nonetheless, Munster held on for an important win ahead of next weekend's clash when Saracens are likely to have their full contingent.
The other Pool Four match today ended in a 40-19 win for Racing 92 over Ospreys.
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