The Hoops suffered some early scares before Scott Sinclair gave them a 16th minute lead.
The Hoops, who made eight changes, suffered some early scares before Scott Sinclair gave them a 16th minute lead.
Thistle, who lost 4-1 to their Glasgow rivals just 11 days ago, caused their hosts more problems than most visitors to Celtic Park this season but couldn't prevent Celtic winning their 12th match in a row.
Celtic, who have a game in hand over nearest challengers Rangers, are now unbeaten in their opening 21 domestic fixtures as they pursue their sixth title in a row.
"It was a very good win for us. I thought in parts of the game it was very good and other parts not so good," Celtic manager Brendan Rodgers said.
"Partick Thistle are a good side and I don't know how they are at the bottom of the league. They have plenty of energy."
Thistle assistant manager Scott Paterson rued his side's missed opportunities.
"It is frustrating as I don't think a lot of teams will come here and create those kind of chances," he said.
"The good thing is that we are creating chances, but we have got to start taking them as they are costing us."
With a congested festive fixture list to contend with, Rodgers had rung the changes, with 18-year-old Calvin Miller handed his competitive debut for the Hoops.
The changes seemed to disrupt the flow of the Scottish champions in the early stages but Partick failed to capitalise. Ryan Edwards should have taken advantage of Jozo Simunovic's slip on the edge of the box but the forward's shot didn't trouble Craig Gordon.
Ade Azeez was then sent scurrying down the right by a ball over the top from Ziggy Gordon but the Celtic goalkeeper got enough on the ball to palm away his fierce angled strike before Liam Lindsay smacked a half-volley over the bar from Sean Welsh's corner.
However, it was the Hoops who took the lead with a move straight off the training ground. Callum Booth was booked for a foul on Cristian Gamboa and Liam Henderson played a quick free-kick into the path of Sinclair near the penalty spot, who clipped a first-time effort high into the net.
Thistle weren't overawed by going behind and should have had a leveller before the break when Azeez went one-on-one with Gordon in the box but the striker dithered before firing and his shot was pushed into the side netting by the keeper.
At the start of the second half, David Amoo's low drive went narrowly wide after taking a deflection off Miller with the unmarked Lindsay flashing a header off-target from the resultant corner.
Partick goalkeeper Tomas Cerny produced a great save as he bravely blocked a fierce strike from Patrick Roberts before the visitors were appealing for a penalty when Edwards's cross appeared to hit the hand of Miller but referee Euan Anderson ignored their pleas.
Thistle missed a golden chance to level matters in the 65th minute when the Celtic defence retreated from the rampaging run of Gordon but the full-back dragged his effort wide of the far post with the goal at his mercy.
Sinclair then came close to his second of the night as he raced through on goal but Cerny produced a great save with his feet to divert the ball around the post.
Thistle pressed until the end but couldn't find a finish as their winless run extends to a seventh match.