Three important points for Cork won with two fine goals in this Munster derby at Turners Cross tonight.
Waterford had the chance to go in front but Vinny Sullivan missed a 25th penalty when his shot went over off the crossbar.
Cork took the lead before the break when Roy O'Donovan scored his 20th goal of the season getting on the end of a good home move, and substitute Leon McSweeney belted home the clincher right at the end.
Cork had to select without international midfielder Joe Gamble who was suspended due to an accumulation of yellow cards, whilst Waterford could not use on loan Cork utility player Cathal Lordan which was part of their transfer agreement.
After a lively start Waterford had an ideal opportunity to go in front when a Sullivan shot struck the outstretched arm of Cork captain Dan Murray, referee Hugo Whoriskey pointed to the penalty spot.
But facing the packed Shed end of Turners Cross former Cork striker Sullivan struck his shot into that crowd off the crossbar.
The homeside then punished the visitors with a well worked goal eight minutes before the break, John O'Flynn fed Liam Kearney with a good pass inside the penalty area, and the winger looked up as he squared the ball for Roy O'Donovan to tap in past Dean Delaney for his 20th goal of the season and 13th minute in the league championship.
O'Donovan almost had a second goal on 51 minutes when he struck a 25 yard shot against the 'Blues' post with goalkeeper Dean Delaney beaten.
Cork full back Billy Woods also flashed a free kick inches wide in a Munster derby that saw Meath referee Hugo Whoriskey flash seven yellow cards.
Roy O'Donovan who was watched by Watford manager Adie Boothroyd had to leave the action early with a leg injury, but substitute Leon McSweeney who recently returned to the club from England, where he had a spell with Leicester, blasted a great second goal after another substitute Denis Behan headed on a long ball into his path.