Locadia opened the scoring after just 15 minutes and, although Zakaria Labyad levelled from the penalty spot, the visitors ran away with it at the Stadion Galgenwaard.
Hirving Lozano restored PSV's lead before the break before Locadia completed his hat-tick with 49th and 68th-minute strikes.
Marco van Ginkel converted an 80th-minute penalty and then, after Giovanni Troupee had been sent off for a foul on Lozano, Locadia also struck from the spot before substitute Steven Bergwijn brought an end to the rout at the death.
Luigi Bruins did the damage as Excelsior got off to a lightning start in their trip to AZ.
Bruins picked himself up to dispatch a second-minute penalty after being fouled inside the box by Jonas Svensson, and then repeated the dose just six minutes later after Ron Vlaar had been penalised for a challenge on Kevin Vermeulen.
AZ battled manfully for a way back into the game, but met stubborn resistance as goalkeeper Birkir Kristinsson kept out an injury-time header from Wout Weghorst to cap a 2-0 win.
Vitesse Arnhem maintained their excellent start to the season as an impressive first-half display laid the foundation for a 2-1 win at Ajax.
Defender Guram Kashia gave the visitors a 21st-minute lead when he headed home Thomas Bruns's cross and it was 2-0 in first-half stoppage-time when striker Milot Rashica fired into the bottom corner.
Nick Viergever reduced the deficit with seven minutes remaining, but it was too little too late.
Groningen striker Oussama Idrissi's second-half header was enough to clinch a 1-0 home win over FC Twente, with Socceroos attacker Ajdin Hrustic watching on from the bench for Groningen.
VVV-Venlo needed a 69th-minute equaliser from midfielder Clint Leemans to cancel out Kingsley Ehizibue's first-half strike and secure a 1-1 draw with Zwolle, withHrustic's international team-mate Terry Antonis also an unused substitute for VVV-Venlo.