Last updated on .From the section Scottish Premiership

Celtic took a step closer to retaining the Scottish Premiership title as they edged to a win over relegation-threatened St Mirren in Paisley.

If Neil Lennon's side beat Livingston on Saturday, Rangers would need at least a point at Motherwell the next day to keep the title race alive.

Timothy Weah's header crashed off the bar and bounced in to open the scoring - his fourth goal since signing.

Olivier Ntcham had a penalty saved but Ryan Christie found a late second.

With Rangers beating Hearts at Ibrox, the gap at the top remains at 13 points with just six games left to play.

Defeats for Hamilton and Dundee leave St Mirren's position unchanged in second-bottom as they fight to avoid the drop.

One hand on the title

St Mirren manager Oran Kearney made six changes from the weekend win over Dundee, his rationale being that his side needed to be lively if they were to cause Celtic problems. And they needed that energy to chase the game after falling behind early.

Weah got up highest to head the ball off the bar and it bounced down before being clawed away by Vaclav Hladky. The St Mirren players were adamant it had not crossed the line, but referee Don Robertson was well positioned and awarded the goal.

Callum McGregor was in inspired form in midfield, at the centre of everything for the visitors. Minutes before the goal his through ball sent Kristoffer Ajer clear in the box, with the Norwegian defender blasting over. Then he picked out Oliver Burke who had just the goalkeeper to beat but horribly skewed his shot wide.

It was one-way traffic and St Mirren needed something to light a fuse under them. They got it when James Kellermann was penalised for handball in the box, awkwardly missing a header and the ball striking his flailing arm. His goalkeeper Hladky guessed correctly to push away Ntcham's spot-kick, before the Frenchman lobbed the rebound off the bar.

It was Celtic's fifth penalty miss of the season, and kept the game alive as the home side attempted to improve on just one win in 32 attempts against the league leaders.

However, Kearney would have been furious at how easily Burke was able to get his shot away despite the attention of three defenders. Anton Ferdinand's challenge in particular was half-hearted. But Hladky again bailed out a team-mate by deflecting the effort with his legs.

St Mirren briefly threatened an equaliser. Cody Cooke picked up a loose ball in midfield and hit a long-range shot that goalkeeper Scott Bain had to be at full-stretch for to push wide.

But the introductions of Christie and Odsonne Edouard breathed new life into Celtic, and the former clipped in a second goal via a slight deflection off a defender.

The game paused temporarily with Hladky somewhat spooked by an missile thrown from the Celtic end. When the game restarted, Paul McGinn had a shot cleared off the line as St Mirren went forward with a vengeance, but it was a short flurry with Celtic comfortably closing in on eight league titles in a row.

Ryan Christie, second right, netted on his comeback from injury

'St Mirren had opportunities' - analysis

Former Celtic goalkeeper Pat Bonner on BBC Sportsound

St Mirren will be disappointed because they had opportunities. And you've got to take your opportunities. They came into the game in the second half. Duckens Nazon will be disappointed after missing a couple of big chances.

'Complacency crept in' - reaction

St Mirren manager Oran Kearney: "You try and stay in the game for as long as possible. We had two or three good chances when it was 1-0. On nights like this, it's important to take them.

"We'd have liked to take something from the game but to come out all even in the league is good for us."

Celtic manager Neil Lennon: "A little bit of complacency crept in. Against any opposition it's always difficult when it's 1-0 but after the second goal we could sit back and relax.

"But it's another step towards the title. I was delighted with the players that came on who all put in very solid performances."