At a glance
The dominant Edinburgh side powered eight ahead of their Glasgow rivals at the top of the Scottish Premiership to strengthen their early-season championship claims and worsen the struggles around the Celtic team.
A superb goal from Kyziridis and Lawrence Shankland's penalty gave the Hearts team a 3-1 lead that the reigning champions could not overcome.
The young defender - among three youth players in the Celtic XI - scored an own goal in the early stages to put Hearts ahead at a bouncing Tynecastle, and it was the youngster's infringement that led to the penalty.
A stylish finish from McGregor of the season had swiftly equalized Hearts' opener, and Benjamin Nygren almost put Celtic in front, opting for finesse over power and allowing Alexander Schwolow to make a crucial stop.
But Derek McInnes' irrepressible Hearts regained dominance to hand Celtic to back-to-back losses for the first time since last year.
It also gives the Edinburgh side a commanding advantage at the summit.
The last time they were so far clear was in the 2005-2006 season under their former manager, when they ultimately finished second - a rare instance that a team has not secured the title after building such an advantage in the last three decades.
The Hearts coach, whose Aberdeen side were second to Celtic on multiple times, has been working hard to downplay title talk, as Hearts seek their first top-flight crown since the 1960s.
Rodgers has seen it all before at the club - both flawless and stuttering starts to a season. He's yet to finish second best.
But on Sunday's evidence, this Hearts team showed they deserve serious consideration.
The Edinburgh side started with the self-assurance of a side undefeated in the league this season - fans' favourite Kyziridis delivered a ball for the striker to fire off target.
Celtic didn't aid their cause with some uncharacteristic carelessness in possession and they faltered under their initial test.
Claudio Braga's header was touched on to a post by Kasper Schmeichel and Shankland's return ball was diverted goalwards by the hapless defender, in for the injured Cameron Carter-Vickers.
The away side found their rhythm and started stringing passes together. From a flowing attack, the midfielder released Tierney to set up the captain, who rolled in.
Aside from the opportunity for Nygren, Celtic struggled to create much for striker Kenny or his replacement Shin Yamada amid the unavailability of stricken attackers their key strikers.
The home team rediscovered their energy and adaptability in attacking from across the final third. Kyziridis, a standout performer of the club's relationship with shareholder Tony Bloom's Jamestown Analytics, fired a low shot past Schmeichel from the just outside the area.
Immediately after, the defender fouled Braga in the inside right channel and Shankland 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 record signing Arne 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 cynical foul.
The Hearts manager: "You see how hard the players work, the team spirit. That's not always enough to win games week in, week out.
"What we have got, is skillful players. You're seeing that from multiple individuals who have been here previously. Some of the new signings are eager to show that.
"We're in a positive moment 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. After the first two rounds is typically a benchmark of your standing."
Celtic manager Brendan Rodgers: "It's a really poor goal from our perspective. We didn't move when the play was recycled as a defensive unit so when they pass the ball, they ought to be caught offside but weren't. We have got to improve with the attempt.
"There's still so many points to play for. It's still so early. It's just nine matches. Clearly, being eight points behind is not what we would want. The positive is there's numerous fixtures to play.
"Our attention must turn on the present and look to find more consistency and better performance in our play."
Celtic are back at home on Wednesday against newly-promoted Falkirk (evening kick-off). At the identical hour in the top division, Hearts are at St Mirren.
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