With their closest rivals Ajax Amsterdam not hosting Excelsior until Sunday, PSV used the opportunity to turn up the pressure and boost morale for Wednesday's Champions League clash at home to Atletico Madrid.
Proepper finished off a string of passes in the third minute and Pereiro brought an end to PSV's horror run of squandered penalties on the stroke of halftime, with supporters clamouring for goalkeeper Jeroen Zoet to take the kick.
The leaders had failed to convert eight of 12 previous penalties this season.
PSV have 59 points from 24 matches, well ahead of second-placed Ajax.
AZ Alkmaar are third on 40 points after a 4-1 win over Groningen. Heracles, the only side to beat PSV in the league this season, occupy fourth position on 38. Ron Vlaar was among the scorers as AZ won a seventh successive league match.
Twente Enschede kept up their good form, moving further away from relegation danger with a 3-0 home victory over bottom club SC Cambuur.
NEC Nijmegen drew 1-1 at Heerenveen in Saturday's other match.
(Reporting by Mark Gleeson; Editing by Tony Jimenez; firstname.lastname@example.org; +27828257807; Reuters Messaging: Reuters Messaging: email@example.com)