Key points
Rampant Hearts powered eight points clear of Celtic at the summit of the Scottish Premiership to strengthen their early championship claims and worsen the malaise around the Celtic team.
A superb goal from Kyziridis and Lawrence Shankland's penalty gave the Hearts team a two-goal advantage that the reigning champions could not overcome.
Dane Murray - one of three youngsters in the Celtic starting lineup - scored an own goal early on to put the home side ahead at a energetic their home ground, and it was the youngster's infringement that led to the penalty.
A stylish finish from McGregor of the season had quickly cancelled out Hearts' opener, and the Swedish attacker almost put Celtic in front, opting for finesse over power and allowing the Hearts keeper to make a crucial stop.
But the unstoppable Hearts side seized control again to consign the visitors to successive league defeats for the first time since last year.
It also gives the Edinburgh side a commanding advantage at the summit.
The last time they were this far ahead was in 2005-06 under their former manager, when they ultimately finished second - a rare instance that a team has failed to win the title after building such an advantage in the last three decades.
The Hearts coach, whose former team were runners-up to the champions on four occasions, has been at pains to downplay championship discussions, as the club seek their maiden league title since 1960.
Rodgers has seen it all before at Celtic - both flawless and stuttering starts to a season. He's never ended as runner-up.
But on the weekend's performance, this Hearts team showed they need to be taken seriously.
The Edinburgh side started with the confidence of a side unbeaten in the league this season - the popular attacker poked a cross in for Shankland to stab wide.
The Glasgow team didn't help themselves with some unusual sloppiness in possession and they buckled under their first real examination.
Claudio Braga's header was touched on to a post by Kasper Schmeichel and Shankland's return ball was diverted goalwards by the unfortunate Murray, in for the absent center-back.
Celtic found their rhythm and started building moves. From one such move, Sebastian Tounekti released Tierney to set up McGregor, who rolled in.
Aside from the Nygren chance, Celtic found it hard to generate chances for lone frontman Jonny Kenny or his replacement Shin Yamada amid the absence of injured forwards their key strikers.
Hearts regained their intensity and versatility in attacking from across the final third. Kyziridis, one of the finds of the club's relationship with shareholder Tony Bloom's Jamestown Analytics, fired a low shot past the goalkeeper from the edge of the box.
Almost straight away, Murray fouled Braga in the inside right channel and the penalty taker converted. And it could've been an more comprehensive victory, had replacement Ageu not been denied by the shot-stopper.
Celtic's second half was partially encapsulated in a couple of moments involving big-money recruit Engles.
The midfielder's wayward free-kick delivery was in stark contrast to his European display in the Europa League win over Sturm Graz and the national team player was then booked for a professional foul.
The Hearts manager: "You see how hard the players work, the togetherness. That's not sufficient on its own to win games consistently.
"What we have got, is good technical ability. You're witnessing it from multiple individuals who have been here previously. Some of the new signings are keen to demonstrate their quality.
"We've got a good thing going at the minute, but it's just one win. It's important for us to keep winning. We've got loads to do, loads to do. Following the initial fixtures is typically a benchmark of your standing."
Celtic manager Brendan Rodgers: "The second goal was disappointing from our perspective. We didn't move when the ball went back as a defensive unit so when they play it, they should have players offside but didn't. We have got to improve with the shot.
"There's still so many points to play for. It's only the beginning. It's only nine games in. Clearly, being eight points behind is not what we would want. The positive is there's so many games to play.
"Our attention must turn on the present and look to achieve greater stability and more quality in our play."
Celtic are returning to their stadium on midweek against newly-promoted Falkirk (evening kick-off). At the identical hour in the Scottish Premiership, the Edinburgh outfit are at their opponents' ground.
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