Hearts moved to the top of the Scottish Premiership with a 3-0 win over Falkirk as Celtic stumbled to a 0-0 draw at home to Hibernian on Saturday.
Aiming to end a 40-year wait for anyone other than Celtic or Rangers to win the title, Hearts are off to a blistering start under Derek McInnes.
The Edinburgh side have also been boosted by a major investment by Brighton owner Tony Bloom, who bought a 29 percent stake in the club in June.
Alexandros Kyziridis fired in a sublime strike to break the deadlock.
Hearts captain Lawrence Shankland added a second before half-time and in doing so became the all-time top goalscorer since the foundation of the Scottish Professional Football League in 2013, with his 163rd in all divisions.
Craig Halkett's header made it 3-0 just after half-time and Hearts' perfect day was rounded off by their Edinburgh rivals denying Celtic in Glasgow.
Hearts sit top on 16 points from a possible 18, two clear of Celtic.
There were further protests by Celtic fans expressing lingering discontent over the club's handling of transfers.
A lack of attacking options available to Brendan Rodgers was exposed as the Scottish champions failed to score for the fourth time in nine league and European matches this season.
Celtic twice hit the bar through Kelechi Iheanacho and Marcelo Saracchi, while Iheanacho also had a goal ruled out for offside.
"I think in every metric in the game we were dominant," said
"I thought today our football was really good, we went through the pitch well but just lacked that killer instinct in the box."
Rangers sit second bottom, 12 points off the top, but can cut the gap on Celtic to seven when they visit Livingston on Sunday.