Celtic's celebratory return to the Champions League after a five-year exodus was ever so slightly dampened as they succumbed to the wizardry of Eden Hazard and the riches of Real Madrid.
Quickfire second-half goals from Vinicius Jr and Luka Modric took the game away from the battling Glaswegian giants before Hazard capped off a fine display with his first goal of the season in the 77th minute.
Ange Postecoglou has brought a certain swagger to Celtic and that identity showed in his team's sensational first-half display. They had won every league match of the season and that momentum carried forward here.
However, their opponents, managed by the wily Carlo Ancelotti, had just won this particular tournament and also boasted an unbeaten start in La Liga. The Spanish giants are masters in delivering lessons of ruthlessness and tonight was no exception. Cold-blooded killers.
Story of the match
Celtic Park was rocking from the off and Liel Abada nearly rubber-stamped that bustling euphoria in the opening 30 seconds of the game, forcing Eder Militao to deflect his goal-bound effort past the post.
Abada had a better opportunity in the 13th minute after a sublime first-time ball over the top from Jota, but the Israeli could only shoot tamely into the arms of Thibaut Courtois.
Buoyed on by their supporters in green and white, Celtic were confident and assertive in their progressive style of play and they continued to bang hard on the door of the European Champions.
First, Jota tested Courtois with an ambitious volley from outside the box before Callum McGregor rattled the post with a 20-yard effort.
Madrid had become accustomed to finding a way in this competition, even when they were lacking in their performance, and Federico Valverde almost paid tribute to that idea on the half-hour mark – whistling an effort wide from the edge of the box.
Ancelotti would have hoped to build on that moment of ingenuity, however, he instead saw his talisman, Karim Benzema, hobble off the pitch after hurting his knee. Hazard, the forgotten former Chelsea star, came on in his place.
And the scriptwriters had their pens at the ready on 41 minutes as the Belgian winger latched onto Dani Carvajal's teasing delivery, but he dragged his close-range volley wide with the goal gaping. Benzema would have been licking his lips at such an opportunity.
Nonetheless, just a couple of minutes later, Hazard did release Vinicius in behind the Celtic defence and Joe Hart did well to save with his legs.
Daizen Maida came on for Abada as a half-time substitute and he should have had his name on the back pages within moments of the restart.
The attacker failed to make a clean contact from little more than six-yards out as Josip Juranovic whipped a beautiful ball between Antonio Rudiger, on at the break for the injured Militao, and David Alaba.
Turning point
From that moment on, though, Los Blancos woke from their slumber, dialled up the tempo, and broke the hearts of their valiant hosts by taking the lead.
It was brilliant football from Madrid, starting from Courtois and playing through the Celtic press. Valverde stormed down the right and curled a delightful low cross to Vinicius, who coolly slotted across Hart on 56 minutes – notching his fourth goal in as many games.
After such a wonderful performance, the home players looked crestfallen as their opponents powered up.
One goal quickly became two after sloppiness in the middle of park from Cameron Carter-Vickers on the hour. Hazard dribbled forward, fed Modric, and the Croatian shifted inside two challenges before finishing with the outside of his right boot. 36 years young!
Ancelotti's men were now happy to sit in and dig deep. The game was done, but the Spanish outfit were not.
Toni Kroos picked out Carvajal at the far post and the right-back cushioned the ball across the box for Hazard, who tapped in a third. Redemption, perhaps, after Hazard missed from a similar position in the opening half.
To Celtic's credit, they picked themselves up and continued to pass the ball with confidence. They rediscovered their composure after momentarily losing their stride following the opening goal. While the game had gone, so had the pressures of throwing something away.
Postecoglou will be looking at others in their group with hope on the back of that performance. The Bhoys played like men and they will be relishing the rest of this European adventure.
It was, however, just another day at the office for merciless Madrid.
Player of the match: Eden Hazard
Celtic would have been more hopeful after Benzema was forced off but Hazard grew into the game. He scored a nice goal and did well to create for Modric's decisive second. There is still plenty of class in those boots.