This performance will hardly have Manchester United quaking in their boots over Tuesday night's meeting as Rangers struggled to impose themselves on a Thistle side yet to record a league victory.
Fortunately for the home side Mikel Arteta scored twice from dead-ball situations with Michael Mols adding the other goal. James Grady scored a late consolation for Thistle which was the least their spirited performance deserved.
Rangers took an early lead after Peter Lovenkrands was fouled by David Lilley as he cut in from the left. Arteta's 20-yard free-kick went over the wall and in off the underside of the bar.
The home team seemed to lose interest after this goal as Thistle came back into the match. Henning Berg did well to clear a Derek Fleming free-kick before Fernando Ricksen was stretchered off.
Jamie Mitchell should have equalised for the visitors though Stefan Klos did appear to touch his shot round the post. Mitchell's header was then held by Klos before the keeper had to be alert to turn a James Grady shot behind at the expense of a corner.
Craig Moore and Michael Ball were booked in quick succession as Rangers' frustration grew. The home keeper was then happy to see a diving header from Grady slip past his post.
The ineffectual Egil Ostenstad was substituted after only 35 minutes before Rangers went two goals ahead against the run of the play with a superb goal. Mols brilliantly controlled Ball's accurate pass before lashing a left-foot shot high past Kenny Arthur.
Christian Nerlinger shot over from a good position just before half-time before he too limped off leaving the Ibrox side with all their substitutes used.
Nuno Capucho's header early in the second half was easily gathered by Arthur before Thistle substitute John Gemmell's dangerous cross was just cut out by Klos.
Rangers wrapped up the points when substitute Jean-Yves Anis brought down Lovenkrands in the box and after Arthur was booked for his protests Arteta coolly dispatched the penalty.
Grady scored near the end when he collected Richard Waddell's pass before shooting high past Klos.