Andy Halliday was left perplexed by former side Hearts' approach as they suffered a mauling at the hands of Celtic on Sunday.

Many viewed the Parkhead club as vulnerable heading into the encounter, having suffered four defeats in their previous five matches.

However, it was the visitors from Gorgie who were exposed time and time again by Celtic's dynamic midfield and attack.

Wouter Vrancken's men were 5-1 down at half-time before shipping two more goals after the break, capping a humiliating afternoon with a 7-1 defeat.

Speaking on the BBC's Monday Night Club, Halliday said his former team were "laughably bad defensively".

"I thought Celtic going forward were absolutely scintillating, but Hearts were the masters of their own downfall," he added.

"For me, Vrancken's approach to going to Celtic Park against a team who everyone thinks are fragile... But in the league campaign over recent years, even though it seems there's been a regression, they are still the best team in the league on their day.

"I thought Vrancken and his Hearts team's approach was so naive. I was as shocked as anyone to see them take a man-for-man approach.

"If you look at the personnel, you're asking Stephen Kingsley, Jordi Altena and Jamie McCart to man-mark Camilo Duran, Callum Osmand and Haissem Hassan.

"A complete and utter mismatch in terms of athleticism and power. Celtic just outran them."