Shannon secured their place in Division 1A for next season with a tremendous bonus point win over Dolphin at Coonagh.
Colm Tucker jnr's side roared into a 21-6 interval lead and must have been wondering why they have not played as well all season.
This was a make-or-break fixture for the Limerick giants who came into the final round of matches in eighth place in Division 1A. They needed to lift their game after a disappointing run of four straight defeats.
Shannon fell behind to a ninth minute penalty from Dolphin captain Barry Keeshan, who broke through the 1,000 points barrier in league rugby last Sunday.
But the hosts hit back with a well-taken 13th minute try from young out-half Gareth Quinn McDonogh which Mossie Lawlor converted.
Keeshan reduced the arrears to 7-6, only for Shannon to dominate coming up to the break. Number 8 David Quinlan touched down following a quick tap penalty.
Then, highly-rated winger Luke O'Dea added a third try from a move that began on the Dolphin 22-metre line and in which four players were involved. Lawlor converted both tries for a 15-point lead.
Munster's Danny Barnes replied, in the second half, with a try for Dolphin when he sped past some sleepy defenders.
Marcus O'Driscoll, who partnered Lawlor at centre, chalked up the bonus point for Shannon who were out of sight at 28-11.
Dolphin, who finished sixth in the table just above Shannon, closed out the scoring with a converted effort from club international player Eric Moloney.
This result, coupled with Garryowen's loss at Young Munster, means that Garryowen finish bottom of the pile and face a promotion/relegation play-off against Buccaneers, the third-placed team in Division 1B.
Referee: Paul Haycock (IRFU)