Key points
Rampant Hearts surged eight ahead of Celtic at the top of the Scottish Premiership to strengthen their early championship claims and deepen the struggles 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.
The young defender - among three youth players in the Celtic starting lineup - slashed into his own net early on to put Hearts ahead at a energetic Tynecastle, and it was the youngster's infringement that led to the spot-kick.
Callum McGregor's classy first goal of the season had quickly cancelled out the first goal, and the Swedish attacker almost put Rodgers' team in front, opting for finesse over power and allowing Alexander Schwolow to save from close range.
But the unstoppable Hearts side regained dominance to consign the visitors to back-to-back losses for the initial occasion since 2023.
It also gives the Hearts a commanding advantage at the top of the table.
The last time they were so far clear was in 2005-06 under George Burley, when they ended as runners-up - one of just four occasions 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 runners-up to the champions on multiple times, has been at pains to play down title talk, as Hearts seek their maiden league title since 1960.
The Celtic boss has seen it all before at Celtic - both perfect and shaky beginnings to a season. He's never ended as runner-up.
But on Sunday's evidence, this Hearts team showed they need to be taken seriously.
Hearts started with the self-assurance of a side undefeated in the league this season - the popular attacker delivered a ball for the striker to stab wide.
Celtic didn't aid their cause with some uncharacteristic carelessness in possession and they faltered under their first real examination.
A headed effort from Braga was tipped onto the woodwork by the Celtic keeper and Shankland's return ball was turned into the net by the hapless defender, in for the injured Cameron Carter-Vickers.
Celtic grew into the contest and started stringing passes together. From one such move, Sebastian Tounekti released the full-back to square for the captain, who rolled in.
Apart from the opportunity for Nygren, the visitors struggled to create much for lone frontman Jonny Kenny or his replacement Shin Yamada amid the unavailability of stricken attackers Kelechi Iheanacho and Daizen Maeda.
The home team regained their intensity and adaptability in creating chances in the opposition half. The Greek forward, a standout performer of the club's relationship with shareholder Tony Bloom's Jamestown Analytics, struck low past Schmeichel from the edge of the box.
Immediately after, the defender tripped Braga in the right side of the box and Shankland scored. And it could've been an even more handsome win, had replacement Ageu not been denied by Schmeichel.
The visitors' performance after the break was partially encapsulated in two incidents involving big-money recruit Engles.
The midfielder's wayward free-kick delivery was in sharp opposition to his midweek exploits in the Europa League win over Sturm Graz and the Belgium international was then yellow-carded for a professional foul.
Hearts head coach Derek McInnes: "The effort from the squad is evident, the team spirit. That's not always enough to win games week in, week out.
"What we have got, is good technical ability. You're seeing that from multiple individuals who have been here previously. Recent additions are eager to show that.
"We're in a positive moment at the minute, but it's just one win. It's crucial for us to maintain this form. We've got loads to do, plenty to improve. Following the initial fixtures is normally an indication 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 line so when they pass the ball, they ought to be caught offside but didn't. We have got to improve with the shot.
"Plenty of matches 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 numerous fixtures to play.
"Our attention must turn on the here and now and look to find more consistency and more quality in our play."
Celtic are returning to their stadium on midweek against promoted side Falkirk (evening kick-off). At the same time in the top division, Hearts are at St Mirren.
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