Neil Lennon's side travelled to Firhill knowing that three points would see them clinch a third consecutive league crown.
And they duly delivered in superb fashion, producing a dominant performance that sees them move into an unassailable 26-point lead over second-placed Aberdeen.
"We're the favourites every year but this was an emphatic win," Lennon told BBC Radio Scotland. "I'm so proud of our goals and our clean-sheets record this season. It's been an exceptional league campaign.
"It's in this club's DNA to win titles."
Striker Anthony Stokes opened the scoring for Celtic, with a further four second-half goals sealing the win and yet another league crown for the Parkhead club.
Liam Henderson and Stefan Johansen put the visitors three goals to the good, with a second from Stokes and one from top scorer Kris Commons finishing off the rout after Christie Elliot had pulled one back for Partick.
Lennon's men have displayed almost unblemished form throughout the campaign, with their only league defeat coming in a 2-1 reverse at Aberdeen last month, a result that ended a 26-game unbeaten run this term.
