Kyle Lafferty justified his return to the Hearts team with the winning goal against Celtic to keep his club top of the Premiership.
Three of the Northern Irishman's 19 goals last season came against the Glasgow club and he has continued that rich vein of form this term.
Hearts lost captain Christophe Berra to injury seconds before half-time but Lafferty executed a sublime first-time finish with the outside of his left foot to break the deadlock on 56 minutes. With interest from Rangers still alive, the striker proved again that he has what it takes to down the league champions.
Celtic enjoyed concerted pressure during spells in the second half but their final ball was not as incisive as normal. After a 4-1 win at Hamilton last week, this result maintained Hearts' 100 per cent record two games into the league campaign.
Lafferty, Jake Mulraney and Michael Smith all returned to Hearts' starting line-up following the Hamilton victory, while Celtic manager Brendan Rodgers made five changes to his side following Wednesday's Champions League qualifier against AEK Athens.
The return leg of that tie takes place on Tuesday in Greece and the Premiership champions needed fresh legs for the trip to Edinburgh. Their goalkeeper, Craig Gordon, was the first to make a save from Lafferty's back-post header after ten minutes.
Hearts then appealed vehemently for a penalty when the Celtic defender Jozo Simunovic seemed to push Steven Naismith in the back with two hands as Jake Mulraney's cross arrived in the box. Referee John Beaton allowed play to continue but those in the home technical area were incensed.
The visitors threatened on 22 minutes after a cleverly-linked passing move down the left involving Kieran Tierney, Jonny Hayes and Scott Sinclair. It ended with Sinclair firing the ball across goal with no hooped jersey in place to convert. Scott Brown then found himself in space from Leigh Griffiths' corner but his eight-yard finish rose over Zdenek Zlamal's crossbar.
The intensity was raised a notch moment before half-time. Set off on a meandering run into the Hearts penalty box and, after evading two opponents, the Scotland striker slipped a low finish under Zlamal – only for Smith to clear off the goal line.
Berra was then stretchered off in considerable pain and replaced by Aaron Hughes. The Hearts skipper fell awkwardly inside his own penalty area and damaged his hamstring whilst chasing Griffiths in the above incident.
There was further controversy when Jonny Hayes tackled Naismith and prompted an angry reaction from the Hearts player. At half-time, this game was still there for the taking.
Zlamal pushed Mikael Lustig's effort over his bar early in the second period. The Czech then had to produce a double save from Griffiths and Callum McGregor after Lafferty had carelessly conceded possession inside his own half.
Just when it seemed Celtic might be exerting some control, Hearts struck. Uche Ikpeazu had not been a huge goal threat himself but he was instrumental in providing the opener. The forward's driving run into the penalty area ended with a neat cutback which Lafferty insolently flicked home from 18 yards with the outside of his left foot.
Efforts from Smith and Olly Lee in the aftermath hinted that the hosts wanted a second goal to put clear distance between them and the opposition. However, as the clock ticked on they began to tire visibly and Celtic edged forward.
The pressure as the final whistle neared continued but Ikpeazu was a useful outball for Hearts. In the end, they saw the game out to spark joyous celebrations at full-time.
Hearts (4-1-4-1): Zlamal; M Smith, Souttar, Berra (Hughes 45), Garuccio; Haring; Mulraney (Bozanic 75), Lee, Naismith, Lafferty (Cochrane 81); Ikpeazu. Unused subs: Doyle, MacLean, McDonald, Morrison.
Celtic (4-2-3-1): Gordon; Lustig, Simunovic, Hendry, Tierney; Brown, Kouassi (Rogic 70); Hayes (Forrest 62), McGregor, Sinclair; Griffiths (Edouard 62). Unused subs: Bain, Ntcham, Ajer, Johnston.
Referee: John Beaton.