Shelbourne's first win in six games edged them closer to a first Premier Division title since 2006 after a stunning second-half crescendo saw off Waterford at Tolka Park.
In this mini run of three games to the finish, a late penalty from Sean Boyd and a stunning Liam Burt strike maintained Shelbourne's two-point lead over Derry and Shamrock Rovers with two games remaining.
Padraig Amond threatened to be the latest to derail Shelbourne's title bid when his penalty put Waterford in front, but Boyd levelled before he struck again from the spot to put Shels ahead ten minutes from time.
Substitute Burt made sure of a crucial three points in sumptuous fashion to reinstall belief that Damien Duff's side can go all the way.
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