ANDY WALKER was left shellshocked as he described Joe Hart's "horrible" mistake to gift RB Leipzig a second in Germany.

The Sky Sports broadcaster was offering commentary updates on the Champions League clash tonight when Hart handed Leipzig the lead with a poor pass.

Celtic had dodged falling 2-1 behind when Dominik Szoboszlai's thundering strike was ruled out because of an offside player impeding Hart's vision.

But seconds later Andre Silva did make it 2-1 after Hart's misplaced pass allowed RB Leipzig to spring an easy attack to take the lead.

Walker was stunned by the major blunder as he branded the error a "horror mistake" from the experienced stopper.

Visibly in shock, as he updated viewers on the score, Walker explained: "Oh you need to see this one, Jules. It is a horrible mistake from Joe Hart.

"He has got very comfortable possession in his own box and he's tried to play a pass that is...

"I can't believe he's tried to play that pass.

"I mean, the weight of the pass, there are three Leipzig players around Greg Taylor and he's tried to play it...I can't believe he's tried to play that pass.

"It's so tight, there's no gap and it's just been played into the path of Andre Silva and slipped it in behind Joe Hart.

"But that's a horrible mistake because Celtic you know just in terms of their general defending - they're without (Cameron) Carter-Vickers tonight, he's been really strong.

"Welsh has been good, Jenz has been good and that's a horror mistake from Joe Hart, 2-1 Leipzig."