At a glance
The dominant Edinburgh side powered eight ahead of Celtic at the summit of the Scottish Premiership to strengthen their early-season championship claims and worsen the struggles around Brendan Rodgers' side.
Alexandros Kyziridis' fine strike and a spot-kick from Shankland gave Derek McInnes' side a two-goal advantage that the reigning champions could not overcome.
Dane Murray - among three youth players in the Celtic XI - slashed into his own net in the early stages to put Hearts ahead at a bouncing Tynecastle, and it was the 22-year-old's foul that led to the spot-kick.
A stylish finish from McGregor of the season had swiftly equalized Hearts' opener, and the Swedish attacker almost put Rodgers' team in front, opting for finesse over power and allowing the Hearts keeper to make a crucial stop.
But Derek McInnes' irrepressible Hearts regained dominance to hand 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 previous occasion they were this far ahead was in 2005-06 under George Burley, when they ended as runners-up - one of just four occasions that a team has failed to win the title having held such a lead in the past 27 years.
The Hearts coach, whose Aberdeen side were runners-up to the champions on four occasions, has been at pains to play down championship discussions, as the club seek their first top-flight crown 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 Sunday's evidence, this Hearts team showed they need to be taken seriously.
Hearts started with the self-assurance of a side unbeaten in the league this season - the popular attacker delivered a ball for Shankland to stab wide.
The Glasgow team didn't aid their cause with some unusual sloppiness in possession and they buckled under their initial test.
A headed effort from Braga was tipped onto the woodwork by Kasper Schmeichel and the follow-up from Shankland was diverted goalwards by the hapless defender, in for the absent center-back.
Celtic grew into the contest and started stringing passes together. From one such move, Sebastian Tounekti released Tierney to set up the captain, who slotted home.
Aside from the Nygren chance, the visitors found it hard to generate chances for lone frontman Jonny Kenny or his substitute Yamada amid the unavailability of stricken attackers Kelechi Iheanacho and Daizen Maeda.
The home team regained their intensity and versatility in attacking from across the final third. The Greek forward, one of the finds of the club's relationship with shareholder Tony Bloom's Jamestown Analytics, struck low past the goalkeeper from the edge of the box.
Almost straight away, Murray tripped the midfielder in the right side of the box and the penalty taker scored. And it could've been an even more handsome win, had replacement Ageu not been stopped by the shot-stopper.
Celtic's second half was partially encapsulated in two incidents involving record signing Arne Engles.
The set-piece from Engles delivery was in stark contrast to his European display in the Europa League win over Sturm Graz and the Belgium international was then yellow-carded for a cynical foul.
The Hearts manager: "The effort from the squad is evident, the team spirit. That's not always enough to win games consistently.
"What we have got, is skillful players. You're witnessing it from a lot of players 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 crucial for us to maintain this form. We've got much work ahead, loads to do. Following the initial fixtures is typically a benchmark of where you are."
The Celtic boss: "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 ought to be caught offside but weren't. We have got to improve with the attempt.
"Plenty of matches to play for. It's only the beginning. It's only nine games in. Obviously, being eight points behind is not ideal. The comfort is there's numerous fixtures to play.
"We now have to focus on the present and look to find more consistency and more quality in our play."
The Glasgow club are back at home on midweek against promoted side Falkirk (evening kick-off). At the identical hour in the Scottish Premiership, the Edinburgh outfit are at their opponents' ground.
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