The last time the final whistle blew at Old Trafford before last night Cristiano Ronaldo had headed straight for the tunnel, consumed by bitter disappointment.

It was becoming a familiar feeling for the 36-year-old, who couldn't hide his frustration as United dropped points against Aston Villa, Everton and Leicester City in the Premier League.

But the beauty of football is there's always another game around the corner, a chance to right recent wrongs, to turn the narrative on its head.

In between those domestic disappointments, Ronaldo has scored the 95th-minute against Villarreal, when United didn't deserve to win, and the 81st-minute winner against Atalanta last night when they most definitely did.

Against Villarreal Ronaldo did his Incredible Hulk impression, tearing off his red shirt to reveal that ripped torso. Last night the celebrations were similar and in the same corner of Old Trafford, but there was still work to be done, time for the game to be closed out.

Deep into injury time as he chased back towards his own goal, he implored referee Szymon Marciniak to blow his whistle. When it finally came Ronaldo sank to his knees, clenched both fists and screamed to the heavens. It was ecstasy.

This is a 36-year-old who has won league titles in England, Spain and Italy, has won the Champions League five times and the Ballon d'Or on five occasions as well. He should be heading towards retirement with a satisfied glow.

But that's not in his nature. Ronaldo hasn't returned to Old Trafford for a bit of romance and an easy end to a glittering career. He desperately wants more trophies and his reactions in recent weeks have been a testament to the desire that still burns within. Even though he's already won all there is to win in the club game, he still wants more, he plays with a burning intensity to succeed that some footballers half his age cannot match.

For all the recent debate about what he does and doesn't offer United, maybe that is the most alluring trait of all. Ronaldo might be a guarantee of goals, he might not press much, but he's another born winner in a squad that has plenty of them.

Right now, maybe that is Ronaldo and United's greatest strength. He's not the only player demanding such high standards. Bruno Fernandes set to the tone for that when he signed from Sporting Lisbon, but Ronaldo is now the embodiment of it.

United beat Atalanta last night partly because they just refused to lose. There was no radical tactical shift at half-time, no obvious change to their game, they just upped the intensity until the Serie A side wilted. It was a comeback borne out of desperation and that led to the show of emotion from Ronaldo at full-time.

The first-half performance, while far from the worst of the season, still highlighted the concerns that exist around Ole Gunnar Solskjaer's United. They're defensively poor with just one clean sheet in 20 games and still look tactically poor at times, but they have world-class players and, perhaps more importantly, they have world-class players who remain absolutely desperate to succeed.

That will only take United so far, but at the moment it might be their greatest strength while Solskjaer tries to fix the longer-term issues.

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