Munster 15 Saracens 9
Ronan O'Gara's right boot helped Munster to a narrow win in this cagey Heineken Cup clash with Saracens at Thomond Park.
O'Gara had a five-from-five kicking return, whereas his young counterpart Owen Farrell missed four of his seven shots at the posts.
Farrell redeemed himself by converting a 79th minute penalty for a losing bonus point which keeps Saracens at the top of Pool 1, albeit with Munster now level on 10 points ahead of next week's return fixture in Watford.
This absorbing encounter was balanced on a knife edge throughout, with Munster gaining the early edge to take a 9-3 interval lead.
The immense physicality spilled over at times, leading to yellow cards for Donncha O'Callaghan and Rhys Gills, while Saracens' lineout creased alarmingly under pressure from the hosts.
With man-of-the-match James Coughlan producing the goods up front, O'Gara hammered over two more kicks to stretch the lead to nine points although Farrell had the final say by coolly completing his penalty hat-trick in the dying minutes.
Saracens welcomed back Alex Goode, Chris Ashton, Brad Barritt and IRB Player of the Year nominee Farrell from international duty.
Amid a back row injury crisis, Munster handed a Heineken Cup debut to Cork youngster David O'Callaghan and a back problem continues to rule out former captain Paul O'Connell.
Munster set the early intensity, Will Fraser being caught offside and O'Gara confidently knocked over the left-sided penalty in the fifth minute for the lead score.
A neatly-worked lineout move put Conor Murray dummying past both Schalk Brits and Charlie Hodgson, however an awkward final pass was spilled by the supporting Simon Zebo.
The first sign of a try-scoring threat from the Englishmen was visible in the 12th minute. Goode countered from deep and linked with Barritt and Ashton with the latter's dinked kick grounded just in time by the retreating Felix Jones.
Farrell failed with his first penalty attempt after Mike Sherry went off his feet at a midfield ruck, and a loose Sarries lineout saw O'Gara drill Munster back downfield.
The first flashpoint, midway through the half, resulted in French referee Pascal Gauzere flashing yellow cards to O'Callaghan and Gill for an off-the-ball dust-up that led to others piling in.
Munster exerted pressure on Saracens' lineout again and turnover ball paved the way for O'Gara's second penalty goal, following good carries from James Coughlan and David O'Callaghan.
The sides swapped penalties coming up to half-time, with Farrell punishing a scrum infringement and O'Gara converting after Ernst Joubert had interfered with Donncha O'Callaghan in a lineout.
O'Gara, who was benched during Ireland's November internationals, drifted a drop goal wide in the last act of a tense and feverish first half.
Saracens made the stronger start to the second period, benefiting from some further indiscipline at the breakdown from Munster. A 37-metre penalty from Farrell increased the heat on Rob Penney's men.
The home forwards produced a storming response, winning a scrum against the head before O'Gara fired over his fourth sure-footed strike from inside the Sarries' 22.
A fifth followed as Munster began to dominate in the possession stakes, with Keith Earls and James Downey probing in the middle and the back row working ferociously as a unit.
Saracens were living off Munster mistakes and Farrell drifted a 44-metre penalty to the left and wide as the drizzle came down.
There was glimpse of Farrell's talent in the build-up with a deft flicked pass to Goode creating the space for Fraser's opportunity. Yet, Munster held out and rebounded for an edgy final 10 minutes.
Howlett and Ashton both threatened on their wings, the latter's touchline dart earning a 75th minute penalty which Farrell sent wide off the left hand upright.
But O'Gara blundered as he pushed the resulting drop-out straight into touch. Sarries steeled themselves for a final charge and the fruits of their labour could yet prove vital when the pool placings are decided next month.