Kyogo Furuhashi stretched to score his sixth goal in six games for CelticCeltic's rousing progress under manager Ange Postecoglou continued as they took a step towards the Europa League group stage with a pulsating victory against AZ Alkmaar.
Kyogo Furuhashi turned in Tom Rogic's superb cross to open the scoring - his sixth goal in as many games since joining.
It was no less than Postecoglou's side deserved after an all-action first half - and Kyogo then teed up James Forrest for the second with a deflected effort.
While overwhelmed at times, AZ created plenty of chances themselves, but a combination of last-ditch Celtic defending and profligacy means they go into the return leg in the Netherlands next Thursday in a difficult position.
Postecoglou's influence on Celtic has grown with each game and the Australian's attacking mantra has brought the best from his players, who have now scored 18 goals in five matches.
It produced a raucous atmosphere at Celtic Park too, with fans loving their team's swashbuckling style.
No player epitomises the change more than summer signing Kyogo, who has already become a hero if the legions of Japanese flags in the stands are anything to go by.
The forward led Celtic's ferocious press and seems to enjoy a fantastic understanding with a revitalised Rogic, who pirouetted away from three AZ players before finding an outstretched Kyogo to produce a fantastic finish in the 12th minute.
Rogic, Liel Abada and Forrest had multiple efforts as Celtic swarmed AZ early on and, despite a drop off in the second period, they eventually claimed a crucial 61st-minute second goal.
David Turnbull won possession high up the pitch and found Kyogo, whose precise pass allowed Forrest to turn and fire a shot that went in off AZ defender Timo Letschert.
Celtic should have had a third with five minutes left, but a sensational double save from visiting goalkeeper Hobie Verhulst denied substitute Odsonne Edouard.
The Dutch side were second best, but threatened to exploit Celtic's lingering defensive frailties. Zakaria Aboukhlal exposed Carl Starfelt inside the opening five minutes, only to flop to the deck too easily before shooting.
Keeper Joe Hart had to prod Vangelis Pavlidis' effort onto a post as AZ targeted the space between Celtic's full-backs and centre-backs. Thijs Oosting also inexplicably side-footed well over from seven yards.
But, despite the scares, Celtic soaked up late pressure to earn an impressive victory.
Man of the match - Tom Rogic
Kyogo was outstanding, but Rogic got Celtic ticking in forward areas and looks a revitalised playerWhat did we learn?
What a difference a few weeks makes. Celtic looked ominously off the pace in exiting Champions League qualifying and losing their league opener, but just a few games later they look a slick attacking outfit.
Rogic looks like the player of old and Kyogo is relentless on and off the ball, setting the tempo which Postecoglou demands. A previously written-off Anthony Ralston continues to grow too.
Defensively, there are still concerns. Starfelt was slack in possession early on and his recovery pace is not quick enough to make amends for his errors. Alkmaar might have punished some of Celtic's sloppy defending had they played more than one competitive game so far this season.
This was definitely Celtic's stiffest test of the season and they passed it with aplomb - but better teams will expose the space they leave when they lose the ball.
However, it is still very early days for Postecoglou and reinforcements are expected to arrive.
What they said
Celtic manager Ange Postecoglou: "I thought it was a cracking game. They took it to us at times, we had to work hard and show resilience, but the pleasing thing for me was we didn't yield or change our approach.
"We were still trying to be brave and even the times it didn't work out, we just got back on the horse and went again. Our reward for that was getting the two goals."
What's next?
Celtic are back in Scottish Premiership action on Saturday, at home to St Mirren (15:00 BST), before the return leg in Alkmaar next Thursday (19:15).
Line-ups
Celtic
Formation 4-3-3
15Hart
56Ralston4Starfelt57Welsh3Taylor
14Turnbull42McGregor18Rogic
11Abada8Furuhashi49Forrest
15Hart56RalstonBooked at 63mins4Starfelt57Welsh3Taylor14TurnbullSubstituted forSoroat 88'minutes42McGregor18RogicSubstituted forMcCarthyat 75'minutesBooked at 82mins11AbadaSubstituted forEdouardat 58'minutes8FuruhashiSubstituted forMontgomeryat 74'minutes49ForrestSubstitutes
1Barkas6Bitton10Ajeti12Soro16McCarthy22Edouard26Urhoghide29Bain30Shaw41Robertson54MontgomeryAZ Alkmaar
Formation 4-3-3
12Verhulst
2Sugawara22Letschert4Martins Indi25Oosting
6Midtsjø10de Wit8Koopmeiners
28Gudmundsson21Pavlidis17Aboukhlal
12Verhulst2Sugawara22Letschert4Martins Indi25Oosting6MidtsjøSubstituted forClasieat 72'minutes10de WitBooked at 48mins8Koopmeiners28GudmundssonSubstituted forEvjenat 72'minutes21PavlidisSubstituted forPokuat 80'minutes17Aboukhlal
