TURIN, Italy -- As time ebbed away, it looked as though Cristiano Ronaldo had done precisely what Juventus signed him to do, following the majestic volley with which he put the Italian champions ahead against his former club Manchester United.
In a tight Champions League game Wednesday against a formidable rival -- by reputation, if not current form -- Ronaldo stepped up to net his 121st goal in the competition, making what appeared to a decisive contribution just when it mattered most.
A pinpoint 50-yard pass from Leonardo Bonucci dropped over the shoulder of the Portuguese forward, who had run behind United's central defenders, and Ronaldo finished exquisitely with a first-time shot.
His 65th-minute strike was not quite at the level of the overhead kick he scored at the same end of this stadium for Real Madrid against Juventus last season -- though it did root David De Gea to roughly the same spot on which Gigi Buffon stood that night in April -- but it was special nonetheless, the kind of goal that would instantly jump into the top five of most other players.
However, his first goal in the Champions League for Juventus ultimately turned out to be no more than b-roll in a highlights compilation of matchday four's best goals, thanks to United's dramatic late fightback, which clinched a 2-1 victory and ensured all three points would head to Manchester.
For Jose Mourinho, who had been taunted by home fans throughout -- no former Inter coach is popular at Juventus, especially one who won the Treble -- the final whistle marked an opportunity to goad his tormentors by holding a hand to his ear. Former United midfielder Paul Scholes suggested on TV in England that it is "sometimes better to win with a bit of class," but Mourinho milked his moment of victory.
For Juventus, the prospect of winning Group H with two games to spare had evaporated and, though they were unlucky to end the game with nothing, they did not dominate and were defeated by a team sitting seventh in the Premier League.
Champions League contenders do not allow themselves to be robbed by inferior opponents, especially at home. Massimiliano Allegri's team conceded an 86th-minute equaliser to Juan Mata's free kick, then succumbed as injury time approached when a defensive mix-up resulted in Alex Sandro's own goal.
It was a worrying conclusion for Juventus, who parted with €100 million to sign Ronaldo as the missing piece in their quest for European club football's biggest prize. Their star man did his bit by scoring, but over the 90 minutes there was something lacking, which must be a concern for everyone connected with the club.
In a season that appears to lack an outstanding team, it feels like now or never for Juventus, especially with Ronaldo approaching his 34th birthday in February. If they do not manage it, their veteran superstar might not have it in him to drag an equally aging squad to continental glory beyond the end of this season.
Allegri's men did not overpower United or blow them away as the likes of Real Madrid or Barcelona have done to teams on their way to recent Champions League titles.
Barcelona have been mesmerising at times, especially with Lionel Messi at the peak of his powers, while Real, with Ronaldo at the sharp end of their attack, brushed aside all challengers on their way to winning the past three Champions League titles.
Juventus are not in the same class, but defeats three years apart in finals against Barcelona and Real convinced the hierarchy at the Allianz Stadium that they needed an X factor. Ronaldo was the expensive roll of the dice, the objective was crystal clear and the rest of the continent took notice.
"They are a big team for many years," Mourinho said. "They bought that player [Ronaldo], they want to win everything, they can win everything, so this is a fantastic victory for us. Even if this doesn't end in a victory for us, I am very happy in the performance of my players against a super team."
And so, while Juventus are unquestionably a team to be reckoned with, their inability to capitalise on Ronaldo's goal by finishing the job suggests they will find it even tougher against the likes of Barcelona, Bayern Munich, Manchester City and even Madrid.
Ronaldo's box-office strike showed he still has magic in his boots, but he is a fading force simply because of the miles and age in his legs. Meanwhile, Giorgio Chiellini and Bonucci are both in their 30s, as is Sami Khedira, while there are also question marks over Wojciech Szczesny's capability as a top-class goalkeeper in the post-Buffon era.
"It's a disappointing defeat, because the team played well," Allegri told Sky Sport Italia. "We need to improve our finishing, because we never manage to finish games off when we're in control. I think it'll do us good in the long run, as we need to learn not to fall asleep in these situations."
Juventus can indeed learn from what happened and remain a team that can dominate and win games easily, but can they beat the very best? The same goes for Ronaldo. He remains a threat against most opponents, but can he do it often enough against the big guns or, as against United, is he now all about brief glimpses of brilliance?
Ronaldo and Allegri's team might just have enough in them to win the Champions League this season, but time is running out, and what happened Wednesday might just be a sign of things to come.