PSV's top scorer Locadia struck in the 14th minute to take his tally to 11 league goals this season and help lift the club to second in the table, six points behind leaders Ajax Amsterdam who have a game in hand.
Mitchel Paulissen equalised before halftime but Roda were sunk by second-half goals from Costa Rica international Bryan Ruiz and former Chelsea defender Jeffrey Bruma.
Vitesse Arnhem's championship challenge received a potentially knockout blow when they lost 3-1 at Groningen.
Richairo Zivkovic, Nick van der Velden and Tjaronn Chery were on target for Groningen to leave fourth-placed Vitesse seven points off the pace.
Danish midfielder Soren Rieks scored in injury time to salvage a 2-2 draw for struggling NEC Nijmegen at Heerenveen but his side remained second from bottom, two points ahead of Roda.
- Sports & Recreation
- Ajax Amsterdam