In front of a big crowd, the Irish side led 15-7 at the break and although the Watford based side staged a fight-back, Munster won 18-16.
O'Gara and Quinian scored tries for Munster with Raluvov going over for Sarries.
In Rugby League, Coventry Bears got their Conference season off to a flying start with a 44-17 win at Derby.
Try scorers were Matt Cooper (2) A. Brown, C Brown, M. Allsopp, B. Powis, T. Watson, M. Cooper, R. Whitehouse