Kenny Miller's fifth goal of the season broke St Johnstone's stiff resistance as champions Rangers took over at the top of the Scottish Premier League.
The visitors took a deserved lead after 25 minutes with a blistering long-range drive from Danny Grainger.
But Kevin Rutkiewicz failed to prevent Sasa Papac's side-footed effort crossing the line eight minutes later.
Rangers dominated after the break and Miller finished clinically after Lee McCulloch threaded the ball through.
The reigning champions had been the better side in the early moments, but a powerful free-kick from Papac that was well smothered by goalkeeper Graeme Smith was their only real threat.
St Johnstone manager Derek McInnes had made three changes from the midweek Co-operative Insurance Cup win over Morton, with Steven Anderson, Jody Morris and Marcus Haber replacing Sam Parkin, Scott Dobie and Cleveland Taylor.
And Haber was particularly impressive, finding space behind the home defence and goalkeeper Allan McGregor had to block an effort from the Canadian at the near post.
St Johnstone were forced to make a change after 20 minutes when Murray Davidson was stretchered off after a clash of heads with team-mate Haber and was replaced with Liam Caddis.
However, Saints were not knocked out of their collective stride against a stuttering Rangers and went ahead when Morris found Grainger with a well-worked corner and the defender's drive flew past McGregor from 25 yards.
The lead only lasted eight minutes and it was a bit of a scrappy affair.
While fellow new signing Nikica Jelavic had to make do with a place on Rangers' bench, Vladimir Weiss had been handed his first start for Rangers in place of the suspended Kyle Lafferty and the on-loan Manchester City winger was proving to be the home side's most creative force.
The Slovak's cross found the head of Stevie Naismith and, although goalkeeper Smith touched it on to the near post, Papac slid in to direct the ball towards the line then Rutkiewicz could do no more than help the ball over the line in his attempt to clear.
That spurred on the home side. But, although they increased the pressure, a shot on the turn from McCulloch, who had started in central midfield in place of Maurice Edu, that bobbled into the arms of Smith was the closest they came before the break.
Rangers began the second half where they had left off and McCulloch fired a few yards wide from 18 yards.
With Rangers having failed to make the breakthrough, Jelavic was given that long-awaited debut following his protracted £4m move from Rapid Vienna, taking the place of James Beattie.
The Croat immediately created an opening with a clever chip to Naismith, but the Scotland forward headed straight at former Rangers goalkeeper Smith from 10 yards.
Rangers finally made their pressure tell after 79 minutes, when McCulloch threaded a lovely ball through to Miller, who calmly turned it into the far corner with the outside of his boot from 15 yards.
The visitors took a deserved lead after 25 minutes with a blistering long-range drive from Danny Grainger.
But Kevin Rutkiewicz failed to prevent Sasa Papac's side-footed effort crossing the line eight minutes later.
Rangers dominated after the break and Miller finished clinically after Lee McCulloch threaded the ball through.
The reigning champions had been the better side in the early moments, but a powerful free-kick from Papac that was well smothered by goalkeeper Graeme Smith was their only real threat.
St Johnstone manager Derek McInnes had made three changes from the midweek Co-operative Insurance Cup win over Morton, with Steven Anderson, Jody Morris and Marcus Haber replacing Sam Parkin, Scott Dobie and Cleveland Taylor.
And Haber was particularly impressive, finding space behind the home defence and goalkeeper Allan McGregor had to block an effort from the Canadian at the near post.
St Johnstone were forced to make a change after 20 minutes when Murray Davidson was stretchered off after a clash of heads with team-mate Haber and was replaced with Liam Caddis.
However, Saints were not knocked out of their collective stride against a stuttering Rangers and went ahead when Morris found Grainger with a well-worked corner and the defender's drive flew past McGregor from 25 yards.
The lead only lasted eight minutes and it was a bit of a scrappy affair.
While fellow new signing Nikica Jelavic had to make do with a place on Rangers' bench, Vladimir Weiss had been handed his first start for Rangers in place of the suspended Kyle Lafferty and the on-loan Manchester City winger was proving to be the home side's most creative force.
The Slovak's cross found the head of Stevie Naismith and, although goalkeeper Smith touched it on to the near post, Papac slid in to direct the ball towards the line then Rutkiewicz could do no more than help the ball over the line in his attempt to clear.
That spurred on the home side. But, although they increased the pressure, a shot on the turn from McCulloch, who had started in central midfield in place of Maurice Edu, that bobbled into the arms of Smith was the closest they came before the break.
Rangers began the second half where they had left off and McCulloch fired a few yards wide from 18 yards.
With Rangers having failed to make the breakthrough, Jelavic was given that long-awaited debut following his protracted £4m move from Rapid Vienna, taking the place of James Beattie.
The Croat immediately created an opening with a clever chip to Naismith, but the Scotland forward headed straight at former Rangers goalkeeper Smith from 10 yards.
Rangers finally made their pressure tell after 79 minutes, when McCulloch threaded a lovely ball through to Miller, who calmly turned it into the far corner with the outside of his boot from 15 yards.
