United Kingdom - Cristiano Ronaldo failed to score on his return to Old Trafford but will leave Manchester with extra belief he can win the Champions League for a fourth straight season after Juventus beat Manchester United 1-0 on Tuesday.
Ronaldo played his part in the only goal, scored by Paulo Dybala, to preserve the Italian champions' 100 percent record in the competition.
United by contrast now face a battle just to make the last 16 despite limited opposition in Valencia and Young Boys in Group H with the spotlight again turned on manager Jose Mourinho's future.
Here are three things we learned:
Despite the concession of a 96th-minute equaliser to Chelsea on Saturday, a positive second-half performance to come from behind on the back of a dramatic 3-2 victory over Newcastle had seen the pressure on Mourinho ease slightly in recent weeks.
However, any hope those performances signalled a turning point in United's season was dispelled as after another poor start, this time there was no spirited fightback.
United have now failed to win any of their last three Champions League home games at what used to be fortress Old Trafford on European nights.
Only an equally poor start to the campaign for Valencia, who have won only once in 12 games, and trail United by two points in Group H means United's position in the Champions League doesn't look critical.
But even if they do make it to the last 16 in the new year, whether Mourinho is still in charge again looks doubtful.
After seven straight Serie A triumphs, Ronaldo headlined an impressive recruitment drive designed to take Juventus one step further in the Champions League than they managed in reaching the final in 2015 and 2017.
So far, so good, a return of three wins to begin their European campaign means Juventus are already virtually secured their place in the last 16 and should comfortably top Group H.
More than just an impressive result, though, the scale of Juve's dominance sent out a message to the rest of Europe.
From the solidity of veteran defenders Giorgio Chiellini and Leonardo Bonucci at the back, the guile of Miralem Pjanic in midfield and goalscoring threat of Dybala and Ronaldo up front, Juventus look the complete team.
"Mr. Bonucci, Mr. Chiellini they could go to Harvard to give some classes about how to be a central defender," said Mourinho.
"It's a team that has everything. They have talent everywhere. Of course Cristiano, Dybala the talent they have in attack, but they have quality all over the pitch."
Forced to field questions over the allegation of rape made against him in the United States for the first time publicly on the eve of the match, Ronaldo insisted he is a "happy man" and would let his football do the talking.
Not afforded the same hero's reception he received on his only previous return to Old Trafford with Real Madrid in 2013 when he scored the winning goal, Ronaldo didn't manage to net his first Champions League goal for the Italian giants.
However, unlike his final years at Madrid where Ronaldo's game was largely reduced to penalty box poacher, he was a far more active presence all over the field.
The Portuguese set up Dybala's winner with a sprint down the right reminiscent of his early days as a tricky winger at United and his cross fell kindly for the Argentine to sweep home his fourth European goal of the season.