Neil Lennon claimed his side's 2-0 win at Motherwell on Saturday was the best performance by any Celtic team he has been involved with.
"That is the best we have played in my time here, as a player, coach or manager," said the Northern Irishman. "I am just annoyed that we didn't come out more comfortable winners."
Gary Hooper's third Scottish Premier League goal of the season was swiftly followed by an Adam Cummins own goal to send Celtic to the top of the SPL. The home side played much of the game with 10 men after Cummins was sent off for fouling Kris Commons in the area, the resulting penalty from Scott Brown being saved by Darren Randolph.
Hearts manager John McGlynn lamented his side's inability to score first after their 3-1 defeat at home to Kilmarnock, which was the visitors' third league win of the season.
"If you get the first goal it's a different complexion on the game altogether. It's the same old story for us in games we've lost," McGlynn said. "Kilmarnock had created very little in the first half and we found ourselves having dominated but going in a goal down."
Ally McCoist was critical of his Rangers side despite progressing to the third round of the William Hill Scottish Cup with a 1-0 win away to Highland League champions Forres Mechanics, where Kal Naismith scored his first goal for the club.
"It's obviously a bit of a helter-skelter we're on at the moment this season and that was evident today," said McCoist. "As much as I'm happy to be in the next round, I don't think I would be doing my job if I didn't register my disappointment at the way we played and passed the ball."