The Scottish champions took all three points at a packed Celtic Park thanks to Alex Oxlade-Chamberlain’s 15th-minute strike in a game that will not live long in the memory.

Hearts’ 3-1 win over Motherwell keeps them three points clear of Celtic going into the split, while rivals Rangers sit a point behind in third, as they head to Falkirk on Sunday.

O’Neill said: “We didn’t play very well. I thought the energy levels looked low, which I think if it had been the last 10 minutes of the game, and you’re holding on to something, I can understand that, but it set in pretty early in the second half, which is a bit of a concern.

“We’ll try to rectify that if we can for next week. We need to. Winning the game was really important, but we didn’t play well.

“You look at what we did this week, we’ll maybe change it a little bit around, but we’ll never know. It seemed to befall a number of us at the same time, which is a bit of a worry.

“We’ve stayed in the hunt, and in fairness to the players they did dig it out in the end, so it was good.

“St Mirren played very well, had control of good wee parts of the game, particularly in the second half, and we just couldn’t get the elusive second goal, a wee bit like Dundee last week, but this time I thought we created much less.

“But we stayed strong, we defended at the corners and free-kicks pretty well, and St Mirren played very well.”

O’Neill took off Callum McGregor in the second half but insists that was not resting him for the Scottish Cup semi-finals next weekend, and said his captain was struggling in midweek, but wanted to play.

He said: “I think, now, a few days off for him and he will be ready. Psychologically, playing the game today was big news for him. Not that we were saving anybody for a semi-final – not at all – that’s in eight days or something.”

St Mirren boss Craig McLeish was left frustrated with the result and wanted his side to have more of a go at Celtic.

“I’d have liked us to try and do a bit more in the final third at times,” said McLeish. “My mentality is I’d rather lose two or three goals in the final 15 minutes, but have a proper go at it – but I get that goal difference is going to be massive.

“It’s difficult right now, because at this stage in the season we need to put points on the board.

“There were so many parts of the performance, especially in the second half, which looked how I wanted it to look like.

“There was a little bit of nervousness in the first half. We spoke about trying to survive the first 15 minutes, because we knew it was going to be lively, and Celtic would come out flying, which they did.

“The disappointing part was we conceded right on the 15th minute, after what was our first good spell of possession in the game.”