But the 'Quins showed an ornery streak that had manifested itself last week in their 29-23 defeat away to Gloucester. They came at Munster in the second half with a feistiness that hadn't really been apparent to that point.
It helped that they got their set piece act together, managing to secure their own ball better and occasionally get at the Munster lineout. They retained possession better and Jeremy Staunton showed himself a far better linekicker with the wind than he had done into it.
The conditions meant it was never going to be a classic. Driving wind and rain placed a premium on doing the basics well and not going too wide through the hand. Grist to the Munster mill when called for.
Not that they started brilliantly. A decent Harlequins rolling maul led to a penalty against Leamy for slowing ball on the deck, but Staunton pulled it left.
The front rows never got settled all day, with numerous penalties and two sinbinnings accruing from it. On 9 minutes, Staunton posted the first score of the day from 30 metres after Horan was pinged for illegal binding. Just two minutes later, the scrum collapsed again and referee Watkins decided he was going to take action early, binning both Horan and Fitzgerald.
A feature of the first half was quick tapped penalties by Anthony Foley, and on 13 minutes he made good yardage before O'Gara moved it wide. The pass over the top to Cullen was half-blocked, but Cullen fed O'Gara on the loop and Horgan had the vital yard to sprint to the line. Although O'Gara couldn't add the points, Munster were ahead 5-3.
Munster got up a good head of steam, opting for kicks to the corner from penalties, but couldn't convert, on one occasion losing ball forward over the line, on another good Harlequins defence drove Munster back.
With Munster well on top, Staunton was binned for a deliberate knock-on in midfield. Only further Harlequins cover denied the penalty try. Something had to give and when the ball squirted out of a Harlequins scrum, Diprose had to take it on but lost it in contact. Williams picked a loose ball, drew the last man with a half-shimmy and offloaded to Leamy who went in on the left. A superb O'Gara convert left it 12-3 to Munster on 25 minutes.
O'Gara continued to pull the levers, using Henderson up the centre on occasion, with Kelly looking sharp at centre too. Another Foley tap led to Harlequins penalty concession in midfield off a move that threatened more. O'Gara did the needful, but turning over at 15-3 was anything but flattering to Munster, even if Harlequins retained possession better in the dying minutes of the half.
Harlequins didn't delay in making use of the wind, Staunton hoisting a good high ball and then a drilled strike into the Munster 22. When the same player converted an angled penalty on 45 minutes, it was very much game on. Nine points was by no means safe into the wind.
A decent Harlequins rolling maul before a Daffyd James break and offload to Harder nearly saw 'Quins make the breakthrough, before terrific Munster pressure defence saw 'Quins unable to capitalise on the scrum five.
Munster came back and when Horgan was high-tackled by Ace Tia Tia, the newly-arrived Harlequins sub hooker was sinbinned, allowing Munster to come back at 'Quins.
But when Staunton nailed another angled kick to reduce the score to 15-9 on 66 minutes, the possibility of an upset became an option. In truth, 'Quins were never really able to make it a likelihood, with Munster's experience seeing them through. Munster didn't concede any further penalty options and Harlequins could never create a tryscoring opportunity. Indeed Munster came closest when Foley nearly capitalised on a Kelly midfield break.
Harlequins desperation shone through a Staunton drop goal attempt on 75 minutes, and despite a concerted effort off the last play of the match when Harlequins went through about 483 phases, Munster held on fairly comfortably for decent start to the annual pilgrimage.