Niall Carew claimed a comfortable victory on his old stomping ground as his Carlow charges beat former side Waterford by 15 points in Dungarvan.
Second half goals by Jamie Clarke, Colm Hulton and Conor Crowley put the Barrowsiders in pole position for a Division 4 semi-final.
Crowley's blistering top corner strike in the fifth minute of injury time was the icing on the cake.
Midfielder Darragh Foley and 2018 All Star nominee Paul Broderick shot four points apiece.
The sides were all square on four occasions before Carlow reeled off four unanswered points.
Conor Crowley also had a goal ruled out on 28 minutes for a square ball, much to the frustration of Carew. Waterford goalkeeper Paudie Hunt was a relieved man as his short kickout had led to the opportunity.
Carlow played with a strong wind in the first half but Waterford began brighter with Stephen Curry and Darragh Corcoran on target inside five minutes. Frees from Paul Broderick and Darragh Foley levelled matters.
Waterford captain Conor Murray then kicked a wonderful point off the outside of the right. Broderick equalised immediately before Crowley gave the visitors the lead for the first time (0-4 to 0-3). Mark Cummins levelled for a third time but then Darragh O’Brien snuck Carlow 5-4 ahead at the first water break.
Jason Curry converted a free for the hosts but they were guilty of six first half wides. Carlow took over for the remainder with scores by Broderick, Foley, Jamie Clarke and John Murphy. Carlow forward Chris Blake was yellow carded for not wearing a gumshield.
Waterford half time sub Jason Gleeson was black carded within three minutes of his introduction and Carlow capitalised with 1-3 while he was off the field.
Foley added two frees before Darragh Corcoran curled over Waterford’s first point in half an hour.
On 46 minutes, Jamie Clarke fired to the far corner of the net to kill off the home challenge.
Paudie Hunt then pulled off a point blank save to deny Crowley.
Super sub Colm Hulton scored 1-1 off the bench including a goal on the hour mark.
Crowley lashed home a cracking goal with the last kick.