Three first half tries helped Lansdowne overcome Shannon at Coonagh on Saturday afternoon, with the victory moving them up to sixth in the Division 1A table.
It was a fine display from Mike Ruddock's young team who were much more clinical than their hosts, particularly during the opening 40 minutes.
Munster's Paddy Butler struck for a late converted try to get Shannon into bonus point range, but Lansdowne out-half Craig Ronaldson kicked a final penalty to leave the Limerick men empty handed.
Shannon got off to the best possible start when out-half Tadhg Bennett landed a penalty from 35 metres out. That strike came after only two minutes but the hosts' lead lasted only six minutes.
A good back-line move after turning over possession brought Lansdowne close to the Shannon line and and their Kiwi flanker Jason Kelly burrowed his way over for a try that Ronalson converted.
Bennett kept Shannon in touch with a splendid penalty from 10 metres in from touch when Lansdowe were penalised for offside.
To the relief of the home supporters, he restored Shannon's lead when he kicked another penalty from almost the same spot in the 18th minute.
Yet, Lansdowne were able to finish the first half in style. Poor Shannon tackling allowed full-back and captain Ross McCarron get over for a try which was too far out for Ronaldson to convert, but he was on target following a well-taken try by scrum half John Cooney.
That seven-pointer came two minutes before the break and for Shannon to have any chance they needed to score first on the resumption, having fallen 19-9 behind.
Stephen Keogh's side were fortunate not to concede a fourth try two minutes in when the Dubliners worked the overlap but the final pass went astray and a certain try was lost.
Butler's effort, two minutes from the end, looked to have salvaged the bonus point for Shannon but Ronaldson put that out of reach, completing his personal haul of 10 points.
Referee: Paul Haycock (IRFU)