The victory was Rangers' second in four matches since the appointment of coach Paulo Sousa and lifted them up to seventh in the table.
It was a deserved triumph for the London side, who created numerous chances before Rowlands broke the deadlock.
On-loan Bolton forward Heidar Helguson made an impact for them on his home debut, although he did miss an early chance when he fired over from Hogan Ephraim's cross.
Michael Mancienne, who spent the best part of two seasons on loan at QPR, then failed to cut out Ephraim's through ball but Patrick Agyemang was unable to capitalise, firing straight at keeper Wayne Hennessy.
QPR continued to impress and Dexter Blackstock sliced over after being released by Helguson's pass, before Agyemang cut in from the left and drove the ball inches wide.
Blackstock limped off and was replaced by Lee Cook, who also had a shot saved by Hennessy.
Despite going close when David Jones curled narrowly wide from a cleverly-worked free-kick, Wolves were fortunate to reach the interval on level terms.
And they again relied on Hennessy to prevent them falling behind just after the break when he blocked Helguson's shot with his legs after the Icelander had latched on to keeper Radek Cerny's long kick.
Cerny then produced two good saves of his own, first diving to his left to push away another Jones free-kick and then stopping Sylvan Ebanks-Blake's close-range header.
And they proved to be crucial interventions because on 62 minutes, Rangers went ahead when Rowlands scored with a stunning 25-yard effort that flew over Hennessy before dipping into the net.
Cerny pulled off two more fine saves to deny Wolves substitute Sam Vokes an equaliser.
He did really well to keep out Vokes' header and in the closing minutes he held the Wales striker's 20-yard drive.