Rangers struggled to break down a well-organised Partick defence but eventually clinched a 2-0 win at Ibrox.
Indeed the visitors could have seriously shown up their Glasgow rivals, but for several crucial saves by Stefan Klos in the Rangers goal.
As it was two quick goals by Michael Mols midway through the second half were enough to preserve Rangers' 100 per cent home record and increase their lead to nine points at the top of the table.
In a first half best forgotten Bert Konterman's long-range effort was easily dealt with by Thistle keeper Kenny Arthur.
Partick wasted a great chance to take an early lead when Maurice Ross played Gerard Britton onside, but Fernando Ricksen saved the day with a great block tackle.
The home side's build-up was too slow and predictable before Peter Lovenkrands tested Arthur with a powerful shot.
Ronald de Boer could only slash his shot wildly past from the rebound. De Boer then found Mols in space, but his cross from the byline failed to reach Lovenkrands.
There was confusion just before the break when Lovenkrands put through a great pass to de Boer but the Dutch striker was pulled up for a marginal offside flag.
The second half started with Mikel Arteta and Mols wasting good chances before Klos rescued Rangers with a super block from Alex Burns after Maurice Ross was well short with a pass back.
Rangers stepped up the pressure but Stephen Hughes pulled his shot wide as did Mols after brilliantly turning Derek Whyte.
Arthur did well to turn a Neil McCann free kick round for a corner before the Ibrox side finally made the breakthrough.
Hughes picked up the loose ball in the box before crossing to the near post where Mols powered his header into the roof of the net from six yards.
Mols added his second after good work by Konterman and de Boer when he shot low under Arthur.
There was still time for Klos to produce a brilliant point-blank save to deny Thistle substitute Richard Waddell.