Aberdeen had displaced the defending champions at the summit on Saturday with a 1-0 win over Dundee United to continue their sensational start to the season.
Celtic edge back in front on goal difference above the Dons, who host third-placed Rangers on Wednesday.
Brendan Rodgers could afford to rotate his side at Fir Park after a draining 0-0 draw at Atalanta in the Champions League on Wednesday.
Lennon Miller twice hit the woodwork for Motherwell inside the first 10 minutes.
But Celtic were able to cruise to victory after Luke McCowan opened the scoring on 27 minutes.
McCowan was one of those given a chance to shine by Rodgers and marked his first start with an excellent run and finish from the edge of the box.
Celtic were without captain Callum McGregor due to injury and stand-in skipper Alistair Johnston headed in Alex Valle's cross early in the second half to double the visitors' lead.
Adam Idah came off the bench to complete the scoring before Motherwell’s Liam Gordon was shown a straight red card late on for a rash challenge on the Irish international.
"It's an excellent performance and result on the back end of a physically demanding week," said Rodgers.
"I thought by the end the players were really comfortable in the game."
Rangers ensured the gap to the top two is just six points after overcoming St. Mirren's resistence at Ibrox.
Mohamed Diomande's opener for the home side was quickly cancelled out by Alex Gogic.
Cerny had scored twice in Rangers' impressive 4-0 Europa League victory over Romanian side FCSB in midweek and the Czech winger proved decisive again when he bundled in Cyriel Dessers' cut-back on 69 minutes.
"We had an ok performance today. But we started with seven new players who weren't in the building two months ago," said under-pressure Rangers boss Philippe Clement.
"They need to get this experience to become better. That's a work in progress so it's important to take these well-deserved points."
Hibernian and Hearts remain tied on points at the bottom of the table after the spoils were shared in a 1-1 draw in the Edinburgh derby.
Mykola Kukharevich puts Hibs in front before teenager James Wilson salvaged a point for the Jambos.