Match ends, Partick Thistle 1, Celtic 2.
Half-time substitute Leigh Griffiths preserved Celtic's 23-year unbeaten run against Partick Thistle to send the champions 11 points clear at the top.
The hosts deservedly led 1-0 at half-time after Mikael Lustig mis-timed a clearance and tugged back Miles Storey, Conor Sammon tucking home the penalty.
Scott Sinclair equalised from the spot after Mustapha Dumbuya felled him.
Both sides had further chances before Griffiths brushed off Adam Barton's challenge to flick home the winner.
New Thistle signing Baily Cargill, on loan from Bournemouth, missed a late chance to equalise when he headed wide from 10 yards.
Thistle, who have not beaten Celtic now in 26 meetings dating back to 1995, remain in 11th place, three points above bottom side Ross County, who travel to Motherwell on Wednesday.
A tactical switch and the introduction of Griffiths ultimately won what was a fabulous contest.
Celtic were thoroughly tested by Alan Archibald's side but Brendan Rodgers' team delivered in style in the end.
The visitors began firmly on the front foot with Odsonne Edouard wasting a good chance and Olivier Ntcham firing narrowly wide from 25 yards.
It appeared a question of simply when Celtic would open the scoring at that stage but Thistle had a game plan to close Celtic down quickly and were rewarded for executing it well in the first half.
Their high-energy approach began to unsettle Celtic's defenders. Lustig was first to buckle under pressure but was rescued by Kristoffer Ajer's alertness.
Storey tested Craig Gordon with a curling effort after another Lustig error but he pounced on a further Lustig lapse with alacrity.
The Swedish defender mis-kicked on the edge of the box, Storey broke clear and was clearly tugged.
Credit to the striker for trying to stay on his feet, but referee John Beaton recognised the foul and awarded the penalty, which Sammon stroked home confidently for his fourth goal in three games.
Rodgers withdrew Lustig at half-time and sent on Griffiths, bringing a change in shape to a back three with two up front.
The restructure worked perfectly and the champions instantly looked sharper and more threatening, and began to swarm forward.
Edouard saw a low shot well saved. Griffiths ran clear but Cerny denied him superbly, racing from his line to block.
The pressure told when Dumbuya, in his first start since April, appeared slightly out of position and caught Sinclair with the winger dispatching the resultant penalty.
James Forrest, Callum McGregor and Kieran Tierney all came close to scoring but it fell to Griffiths to settle matters.
He collected Scott Brown's cutback and danced towards the by-line past Barton's challenge, showing great composure to dink a left-foot shot past Cerny.
It was a crushing blow for the home side, who put so much into the match but ultimately couldn't sustain their performance.
They did have two late chances with the impressive James Penrice and debutant Cargill both going close.
For Celtic, a genuine examination which they answered emphatically in the second half to move 11 points clear of Aberdeen, who travel to face Rangers on Wednesday.
Partick Thistle manager Alan Archibald: "I thought we were a bit tentative in the first 15 minutes, but the belief grew and the more they won the ball back and created a couple of opportunities, we saw a different side.
"There were positives to take, but the overriding emotion is disappointment because we have taken nothing from the game.
"By the law, I think it should have been a sending-off [when Lustig brought Storey down for Thistle's penalty]. That's a bit disappointing because it might have been a different outcome.
"It allowed them to change their shape in the second half and Leigh Griffiths came on and changed the game."
Celtic manager Brendan Rodgers: "It was a good test. Not too many times in domestic football do we go behind.
"There is an expectancy that Celtic are going to win four or five-nil every week, but teams are well organised and they are going to make it difficult for us.
"In the first half we could have had at least two goals but we didn't take our chances and they had something to hang on to with the penalty. But our reaction was very good and it showed the spirit and quality in the team.
"I will be very disappointed if we don't [sign one or two more players this month]. But the people behind the scenes are working very hard.
"We need players of quality if we are going to do anything in European football, and not just domestically. So we have to take time to find the right ones."
- 7SpittalSubstituted forBartonat 56'minutes
- 39StoreyBooked at 75minsSubstituted forErskineat 77'minutes
- 18SammonSubstituted forDoolanat 71'minutes
- 23LustigBooked at 33minsSubstituted forGriffithsat 45'minutes
- 11SinclairSubstituted forSimunovicat 77'minutes
- 22EdouardSubstituted forBittonat 84'minutes
- 24de Vries
- John Beaton
- Shots on Target
Second Half ends, Partick Thistle 1, Celtic 2.
Corner, Celtic. Conceded by James Penrice.
Callum McGregor (Celtic) wins a free kick on the right wing.
Foul by Andrew McCarthy (Partick Thistle).
Leigh Griffiths (Celtic) wins a free kick on the right wing.
Foul by James Penrice (Partick Thistle).
Attempt missed. Baily Cargill (Partick Thistle) header from the centre of the box is close, but misses to the right following a corner.
Corner, Partick Thistle. Conceded by Jozo Simunovic.
Attempt blocked. James Penrice (Partick Thistle) left footed shot from the left side of the box is blocked.
Attempt missed. James Forrest (Celtic) right footed shot from the right side of the box misses to the left.
Substitution, Celtic. Nir Bitton replaces Odsonne Edouard.
Attempt missed. Leigh Griffiths (Celtic) left footed shot from outside the box is close, but misses to the right.
Scott Brown (Celtic) wins a free kick in the attacking half.
Foul by Ryan Edwards (Partick Thistle).
Attempt missed. Odsonne Edouard (Celtic) right footed shot from the centre of the box misses to the right.
Corner, Celtic. Conceded by Baily Cargill.
Substitution, Celtic. Jozo Simunovic replaces Scott Sinclair.
Substitution, Partick Thistle. Chris Erskine replaces Miles Storey.
Kieran Tierney (Celtic) wins a free kick on the right wing.