A second-half volley from Kyle Lafferty clinched an enthralling victory for Hearts over defending champions Celtic.
The Northern Irishman produced a stunning finish on 57 minutes from the edge of the box to fire the Tynecastle club to their second win in two games.
Lafferty had two efforts saved in the first half by Craig Gordon while Mikael Lustig, Leigh Griffiths and Callum McGregor all went close for Celtic.
But Craig Levein's side held on to go clear at the top of the Premiership.
Seven players were booked during a fiery encounter including Steven Naismith, who appeared to kick out at Jonny Hayes on the stroke of half-time.
While it was a successful afternoon for the Edinburgh club, they finished the game without captain Christophe Berra, who went off just before the break with a hamstring injury.
Rodgers rests key men
With Celtic's Champions League future anything but certain following the 1-1 draw with AEK Athens earlier in the week, Brendan Rodgers dipped into his squad and rested some key players.
As his frustrated search for new players continues, he wouldn't be drawn on whether he thinks the current squad is strong enough to fight and win on two fronts. On this showing, he'll be concerned.
Jozo Simunovic looked slack for most of the afternoon and he gave Hearts possession that led to the goal. Uche Ikpeazu did well with the cross and Lafferty's finish was exquisite but the mistake certainly led to the chance.
Kouassi Eboue struggled up against a Hearts midfield that fought and scrapped for everything in a fierce contest that was fought mostly in the middle of the park. Jonny Hayes was favoured over James Forrest on the right but that didn't work out either.
The visitors looked slicker and more dangerous when the big boys emerged from the bench but by that time it was too late. Making so many changes against an impressive Hearts side was always going to be a gamble. In the Gorgie sunshine, it backfired for the champions.
'All about Hearts'
Much will be made about what this means for Celtic, but the afternoon belonged to Hearts. Their performance provided evidence that they could be ready to live up to their pre-season hype.
As questions continue to be asked about Celtic's lack of summer signings, Hearts' new acquisitions continue to look the part. Peter Haring, Ikpeazu and Ben Garuccio in particular have added real quality to a squad that was already looking more than decent.
Levein spent last year bringing on a number of academy players but this season that nurtured talent is being complimented by some experienced professionals who have the ability to change and win games.
Ikpeazu looks the pick of the bunch and as well as terrorising defences and scoring goals, he has also allowed the Hearts fans to believe in life after Lafferty. The Northern Ireland international may well stay but if he moves on to Rangers, those down Gorgie way have a new hero anyway.
On the final whistle, Levein leapt around the touchline like an excited eight-year-old on Christmas morning but his summer signings show the old head knows exactly what he is doing. On this showing, he may finally have a squad to match his ambitions.