Shannon jumped two places up to second in the AIB League Division One following an emphatic 48-8 victory over Clontarf at Thomond Park in the only senior match played throughout the British Isles on Sunday.
The home side held a slender 10-8 win at half-time but ran in four second half tries to claim maximum points.
The first Shannon try was a breakaway effort from David Quinlan after just four minutes, converted by Andrew Thompson.
A slender 10-8 lead at half-time was heavily added to in the second half as Clontarf fell away.
Peter Stringer came on for Cormac O'Loughlin at scrum-half, and Mossy Lawler and John Lacey got the next Shannon tries.
Stringer scored the bonus point try, and Anthony Foley and Jason Hayes finished the rout, with Thompson's five conversions and two penalties added to by one from David Delaney, as Shannon maintained their winning start to the league season, five points behind leaders Cork Constitution with a match in hand.
Munster's ex-Wallaby lock John Langford was a notable absentee for Shannon, at home in Australia for Christmas, but he was not missed against a Clontarf side that offered little once their resistance had been broken.