PSV sunk by last-gasp Den Haag goal
Verhoek scored from a tight angle to hand PSV their third league defeat of the season after 22 matches and they could be knocked off the top of the table on Sunday.
Ajax Amsterdam, 2-0 winners over Graafschap Doetinchem on Friday, are in third place with 44 points ahead of Groningen.
Sixth-placed AZ Alkmaar, on 37 points, dropped off the pace after losing 2-1 at lowly Excelsior Rotterdam having led 1-0 at half-time through Kolbeinn Sigthorsson's 10th minute goal.
Tim Vincken equalised with a penalty in the 65th and Jordy Clasie won the match 10 minutes from time when his free-kick from 40 metres was misjudged by Argentine goalkeeper Sergio Romero.
Heerenveen and NEC Nijmegen played out a 0-0 draw.