Two goals from former Waterford United striker Michael Rafter saw Dundalk remain in the top flight for next season, as they won the promotion/relegation play-off second leg at the RSC.
Played in front of nearly 3,000 fans, the man from Tipperary scored in each half to see his former team-mates remain in the first division for at least another year.
He fired home the first goal right on the half time whistle and won the match for Dundalk and their great travelling supporters with a second goal on 68 minutes.
Before kick off the tie was perfectly balanced, with the sides having drawn 2-2 in the first leg at Oriel Park on Tuesday night.
Lorcan Shannon had given the Louth club the lead in that game, with Waterford fighting back to lead with efforts from Paul Phelan and Ben Ryan in the second half.
Dundalk levelling that encounter with a Stephen McDonnell shot from outside the penalty box.
The visitors who had Stephen Maher sent off in the first leg, made a number of changes with Paul Whelan, Stephen McDonnell, Gary
Shanahan and Robbie Gaule in the starting eleven.
The home side also made four changes, with Seamus Long and John Frost returning after suspension, Ben Ryan and striker Daire Walsh also had starting places.
Played in front of the very big home crowd, the visiting side should have scored after 22 minutes but Mark Griffin volleyed an eight-yard shot over the Waterford crossbar.
Then Dundalk scored right on half time, a long ball from captain Chris Shields found striker Michael Rafter who drilled a low left-foot shot to the net from 12 yards, much to the delight of the travelling fans.
Waterford came out fighting at the start of the second half, and there were appeals for a penalty kick when 18-year-old striker Sean Maguire
went down in the penalty area referee Padraig Sutton was not impressed and booked the Waterford man for diving.
Then Darius Kierins’ side struck on the break for a crucial second goal.
Rafter ran from the half way line with the defenders of his former club giving chase before shooting low past Packie Holden.
Substitute Nathan Murphy nearly scored a third goal but his shot hit a post.
So after going 18 games without a league win before defeating Bray on the last day of the season, Dundalk will play in the Premier division in the 2013 season.
WATERFORD: Packie Holden;Dylan Mernagh,David Breen,Seamus Long, John Frost;Ben Ryan (Aidan McGrath 73),Gary Dempsey,Peter White (Conor Coad 78), Paul Phelan (Jack Doherty 55), Sean Maguire,Daire Walsh.
DUNDALK: Peter Cherrie;Chris Shields,Eoghan Osborne,Liam Burns, (Mark O'Brien 75), Paul Whelan;Lorcan Shannon,Stepen McDonnell (Peter Thomas 89), Robbie Gaul,Gary Shanahan (Nathan Murphy 60); Michael Rafter,Mark Griffin.
Referee. Padraig Sutton(Clare).