Celtic kept the pressure on Scottish Premiership leaders Hearts with a 1-0 win over St Mirren.
Alex Oxlade-Chamberlain's first-half strike was enough for Martin O'Neill's side to move above Rangers into second and remain three points behind Hearts, who earned a late victory over Motherwell.
Celtic were far from their best despite a fast start that saw Oxlade-Chamberlain fire low into the bottom right corner after just 15 minutes, having had one ruled out for offside.
St Mirren were only afforded one shot on target as the hosts missed chances to extend their lead. Substitute Kelechi Iheanacho poked wide from close range in the second half with their best opportunity to wrap up the points, but they ground out a gritty win.
This was the first time these sides had met since St Mirren stunned Celtic with a 3-1 win to lift the Premier Sports Cup back in December, but a repeat of that never looked likely.
The Green Brigade were allowed back into Celtic Park for the first time since November and were in fine voice, for what was a dress rehearsal for next week's Scottish Cup semi-final.
After a period of relentless Celtic pressure, the hosts thought they had taken the lead after five minutes when Callum McGregor's shot was parried by Shamal George, with Oxlade-Chamberlain burying the rebound, only for an offside flag to go up.
St Mirren's Jonah Ayunga fired wide of the left post after making a mazy run into the box, and Miguel Freckleton had a shot saved by Viljami Sinisalo at the bottom left corner on 13 minutes as the visitors tried to make their mark.
But Celtic took the lead in the 15th minute when Benjamin Nygren found McGregor and when his shot was blocked by Alex Gogic, Kieran Tierney picked out Oxlade-Chamberlain, who rifled into the bottom right corner.
Tomas Cvancara nearly doubled Celtic's lead after 28 minutes as he slid in for Daizen Maeda's cut-back from the left, but collided with George, who received treatment for four minutes, before being replaced by Ryan Mullen on 32 minutes.
Mullen was called into action after 36 minutes to block from Cvancara, after good play down the left from Maeda. Nygren tried his luck with a rising shot a minute later, but Mullen saved at the left post.
St Mirren's Mikael Mandron headed a Declan John corner over in first-half stoppage time.
The second half was much more of a midfield scrap, with few chances created by either side. Iheanacho missed the best opportunity at the near post from a low cross.
St Mirren's Manchester United loanee Jacob Devaney tried his luck from distance after 82 minutes, but it was not a problem for Sinisalo, who also saved a low effort from Roland Idowu five minutes later.
Celtic manager Martin O'Neill told Your Site:
"We won the game which was the most important thing but we lacked energy. Second half, we surrendered possession quite easily and we allowed St Mirren strong phases of the game. They played very well.
"It was the energy that was concerning me most. We didn't seem to have that.
"Sometimes it happens. You're chasing the title, we're playing catch-up all the time. We've got no room to manoeuvre. I just felt when we got the first goal, we had to cement it and get the second. We didn't do that and then you're inviting teams to come on to you.
"We did well to keep a clean sheet."
St Mirren boss Craig McLeish told Your Site:
"Disappointed with not taking any points from the game. Where we're at in the season, we have to put points on the board. There were so many parts of our performance, especially in the second half, where that's how we wanted to play.
"We're missing that little bit in the final third, a little bit of creativity, a spark, to create some more chances from open play.
"I have to remember where we're at and who we were playing because it's such a difficult place to come and pick up points."
