But Rangers and their second-bottom hosts were unable to create many more chances on a bumpy Perth surface.

"It was not a beautiful game," manager Van Bronckhorst said.

"It was all about the duels and the fighting. Second half was just about surviving this game. It was really difficult to play our normal game on this pitch."

While Rangers ended a run of three straight draws - and four without a win in the league away from home - defeat for St Johnstone means the Perth side fall nine points from relegation safety.

Aberdeen, beaten by Hearts, are now the side closest to Callum Davidson's team in the relegation play-off spot after Ross County's win at Motherwell.

Rangers looked determined to make amends for Sunday's relinquishing of a 2-0 lead to Motherwell as they dominated early possession to such an extent that they had the ball in the net before their hosts had managed to string any passes together.

Alfredo Morelos' clever flick from a Connor Goldson pass set Kamara through on goal with only Elliot Parish to beat and the Finland midfielder calmly side-footed past the goalkeeper.

That should have taken some of the pressure off the visitors after missing out on a chance to narrow the gap on Celtic on Sunday, but the slackness that allowed a Motherwell fightback gradually crept into Rangers' play as an increasingly wet and rutted pitch - and St Johnstone's willingness to battle for every loose ball - became a leveller.

The hosts had their moments. Allan McGregor's strong hand prevented a low drive from Jacob Butterfield curling inside the upright before the break, while fellow midfielder Ali Crawford just failed to react in time to pounce on a mix-up between the goalkeeper and Rangers captain James Tavernier.

However, any nervousness experienced by the hosts was down to the atrocious surface and their own inability to add to their lead.

A Morelos toe poke against a post and a Scott Arfield drive touched wide off Parish's fingertip being the closest they came and they will be relieved just to leave the rutted pitch without their title challenge being further damaged.

Man of the match - Glen Kamara

On a night where few were able to shine, Kamara provided the one moment of real composure for his goal

What did we learn?

Van Bronckhorst kept to his philosophy of continuity despite Rangers' hectic domestic and European schedule and the disappointment of dropping two home points on Sunday.

Leon Balogun's return to central defence, with John Lundstram pushed back into midfield and forward Fashion Sakala dropped to the bench, provided the solidity needed on a night when brute strength was required more than anything.

However, despite now being unbeaten in eight outings since losing to their city rivals, there will be concern that the reigning champions were again unable to record a more comfortable win over lesser opposition.

Davidson will have gone into the match more in hope than expectation considering Saints have not beaten Rangers now in 13 league meetings and 15 visits to McDiarmid Park.

However, having failed to go four games unbeaten at home for the first time under his watch, the big concern will be the fact the sides above keep edging further outwith their reach.

What they said

St Johnstone manager Callum Davidson: "Against the Old Firm, you've got to keep it tight for the first 25 minutes and we gave them an easy goal. From there, the players did really well and gave it a real go.

"They played it forward and tried to do the right thing. I'm disappointed with the result, but I'm also pleased with a lot of aspects of the game. That attitude tonight will take us a long way and we need that for 90 minutes every week."

Rangers manager Giovanni van Bronckhorst: "We wanted to leave here with the three points and that's the most important thing.

"We knew it was going to be hard given the circumstances, but we had the early goal - it was a great move, a great pass and a great run from Glen - and had a couple of other chances."

What's next?

St Johnstone visit Hibernian on Saturday as Rangers host Aberdeen (both 15:00 GMT).