This was Waterford United's first home win since they beat Dundalk last October and it lifts the Blues, temporarily at least, off the bottom of the table.
United's goal came on 78 minutes when substitute Barry Wood crossed from the left and the hardworking Karl Gannon got in behind his marker, Thomas Dunne, to head a low hopping ball into the net. Rovers had the best of the first half and Jason Sherlock, Peter Murray and Billy Woods could all have scored but their final touch let them down.
United only had one real chance in the first half and they almost scored against the run of play on 45 minutes. Tim McGrath put Dominic Iorsa through but Rovers' goalkeeper, Tony O'Dowd, produced the save of the game to deny the former Nigerian international from eight yards.
Even though they had to defend furiously in the end the second half belonged to United. Brian Flood, Mark Reid, Alan Kirby and Wood all went close before Gannon made the vital breakthrough.
WATERFORD UNITED: Devine, Smith, Frost, Flood, Riordan, McGRath, Kirby, Iorsa, Gannon, Harkin, Griffin. Subs: Reid for Iorsa (54 mins), Wood for Griffin (75 mins), Kabia for Gannon (89 mins).
SHAMROCK ROVERS: O'Dowd, Palmer, Dunne, Brazil, Whelan, Colwell, Treacy, Woods, Sherlock, Murray, O'Connor. Sub: O'Meara for O'Connor (80 mins). Referee: J Stacey (Athlone).
The financial clout of Celtic and Rangers was emphasised yesterday when the Old Firm sealed a £13 million four-year deal with American cable TV company NTL. The shirt sponsorship contract far exceeds anything seen in Scottish football and the money will be split between both clubs.
Now Celtic and Rangers are hoping the deal will lead to a greater worldwide audience with pay-per-view possibly a future option. Celtic managing director Fergus McCann said: "We can use this connection with NTL to get to other audiences.
"NTL are a young, dynamic company investing heavily in Scotland and creating many employment opportunities. Its image is one that Celtic can feel proud to display on its shirts."
