Celtic 1-2 Rangers: Neil Lennon says his side must be 'psychologically better'
Celtic need to play "psychologically better" in derby matches, says manager Neil Lennon, after their 2-1 Scottish Premiership home defeat by Rangers.
The champions remain top of the table but their lead is reduced to two points having played a game more than their rivals.
It was a first home Old Firm loss for Celtic in the league since 2010.
"There's a little bit of inexperience, but psychologically we need to play these games better," said Lennon.
"We've got January coming up, we'll look to add to the squad. There's no panic here. We've been absolutely sensational basically since August.
"We're at the same sort of juncture as this time last year. If we get the same response as we did last year we'll be absolutely fine."
The loss ended a run of 11 straight league wins for Celtic, who are chasing a record-equalling ninth straight league title.
Lennon's side survived a scare to clinch the League Cup earlier this month, having been largely outplayed by Rangers in the final at Hampden.
The Northern Irishman spoke pre-match about the need to start better in this encounter but his team did not respond, passing up the chance to take the lead when Ryan Christie missed a penalty.
Moments later, Ryan Kent gave Rangers the lead and Nikola Katic headed home the winner in the second half after Odsonne Edouard had levelled the match with a controversial deflected goal.
"In the throes of the game, we weren't great," Lennon told BBC Scotland. "Non-reactive to things and we couldn't get our wingers into the game, hence we changed the system a little bit.
"But we can't give away cheap goals the way we did today, especially the second one. To give Katic that amount of space is really poor from us.
"It just means it is game on. If Rangers win their game in hand they will have a one-point cushion. There is nothing in it.
"It's a test of character now which is good. It is not the time to be over-critical."