PSV have 36 points after 15 matches, two ahead of Ajax, who entertain Utrecht on Sunday and have two games in hand.
Midfielder Theo Lucius gave PSV the lead after two minutes, but seven minutes before the break RKC defender Virgilio Teixeira levelled.
Ten minutes into the second half Arjen Robben restored the Eindhoven lead with a brilliant goal from a difficult angle and a second strike by Lucius settled the game with 15 minutes to go.
Twente Enschede striker Blaise N'Kufo gave his side a 2-0 lead in the first half hour against fourth-placed Feyenoord, but a minute before halftime Dirk Kuijt pulled one back, heading home a corner kick.
Collins John restored the two-goal lead early in the second after he beat goalkeeper Patrick Lodewijks with a magnificent curved shot into the top right corner.
Sjaak Polak made it 4-1 from the penalty spot and Chilean Sebastian Pardo's consolation came four minutes from time.
Relegation strugglers ADO Den Haag suffered their 10th defeat of the season, going down 1-0 at home to Willem II Tilburg. Northern Ireland's James Quinn scored the winner on 34 minutes.
