Two second half goals - a wonder strike by Ismail Aissati followed by a penalty from Siem de Jong - were enough to see the three points stay in Amsterdam
The hosts made three changes to the side that beat Den Haag 2-0, with Daley Blind, Eyong Enoh and Jody Lukoki replacing Dico Koppers, Theo Janssen and Araz Oziliz in the starting XI. They were also without top scorer Miralem Sulejmani , who is out for the rest of the season after undergoing knee surgery following his injury against Roda JC earlier this month.
The opening 45 minutes had little in the way of clear-cut chances, with the first real effort arriving five minutes before half-time.
The effervescent Aissati found time and space down the PSV right, skipped past Georgino Wijnaldum on the edge of the area and hit a stinging effort straight into the arms of Przemyslaw Tyton.
But as Ajax tried to up the tempo in a bid to carve open a resilient PSV defence, the visitors began to slow the game down with a number of cynical challenges.
Dries Mertens had already been booked for a late tackle on Anita, and it was in the closing minutes of the half when Ajax produced their best moment thanks to another clumsy foul, by Kevin Strootman on the hosts' dangerman Christian Eriksen.
The resultant free-kick was teed up by the Dane for team-mate Jan Vertonghen, who hit the ball first time hard and low which Tyton did well to get down low to palm away from danger.
Soon after the interval either side could - and probably should - have taken the lead.
First PSV wasted a golden opportunity as striker Tim Matavz broke the offside trap but saw his strike blocked heroically by the onrushing Vermeer.
Then it was Ajax's turn to go close, with Eriksen creating a chance out of nothing, fizzing in a strike from range, only the ball hit the wrong side of the side-netting.
Just over 10 minutes into the second half and Aissati produced a moment of magic to put the hosts ahead. A quick free-kick from Eriksen was played to the 23-year-old who took little time in whipping the ball over the wall and into Tyton's top-left corner. It was Aissati's first goal for Ajax since 2010 and it became the catalyst of things to come.
Substitute Lorenzo Ebecilio wasted another chance for Ajax before De Jong doubled their lead from the penalty spot.
Aissati had once again got in behind the PSV defence and, after a tussle with left-back Marcelo, the winger was brought down by the Brazil defender giving the referee no option but to award a penalty. Up stepped de Jong who nonchalantly slotted the ball past Tyton for his seventh league goal of the season.
Ajax seemed to take their foot off the gas but PSV, for all their possession, failed to test Vermeer in the visiting goal in the closing stages.
The win was the reigning champions' seventh consecutive victory, moving them above Twente into second place; defeat for Phillip Cocu's side leaves them fourth and with it an uphill struggle in the race for the title.