Perhaps all Sir Alex Ferguson, sport's most famous and combustible -septuagenarian, needed in order to calm his volatile nature was the sight of Nemanja Vidic orchestrating Manchester United's back four. Just three days after his touchline explosion at the officials in the 4-3 victory over Newcastle, and two days short of his 71st birthday, Ferguson cut a far more serene figure as he left his dugout to oversee the closing stages of a relatively anxious victory.
The big difference between the two fixtures, however, was not so much the behaviour of the manager but the composure of a United defence which, with Vidic at its core after his recovery from knee surgery, looks far more capable.
For just the second time in 18 league and cup games, United emerged from this contest with a clean sheet although the 28 Premier League goals they have conceded to date represents an appalling effort by their supreme standards. In three of their last four title-winning seasons, United have conceded less than that in the entire campaign.
"After the drama of the Newcastle game it was the sort of gritty win you need in a title race," said left-back Patrice Evra. "It was an unbelievable game against Newcastle but today was more about not conceding a goal, a solid performance and we finished with a clean sheet and three points. That was the most important thing.
"It is good for the confidence to keep a clean sheet. But I am more worried about winning games than conceding goals. I'm a defender, I don't like to concede goals, but it is not only about the defence it is about the whole team.
"Maybe this is going to sound a bit bizarre what I am going to say - I feel we were more awake defensively last season and we conceded less goals. But this season every time our opponents shoot they always seem to score. I know sometimes it is about our concentration and we can do much better but I'm not worried about that, I'm just worried about winning games."
The reasons for United's defensive shortcomings have been debated long and hard, with even Ferguson himself admitting he has been at a loss to explain them fully. Suffice it to say, much store has been placed upon the return of Vidic, who has lost much of the last two seasons to injuries.
A commanding seven-point lead at the top of the Premier League has been amassed despite, not because of, Ferguson's defence and the temptation is to assume that the Serbian's return could leave United with a clear path towards a 20th title in May. The truth is rarely so straightforward, of course, and, at the age of 31, Vidic hardly sounds full of optimism that he can enjoy an injury-free -second half of the season.
"The doctor is managing the games I am playing at the moment," said Vidic. "Over the first two or three months I have to really look at that because sometimes I might have a reaction. This is a process I have to go through."
There is also the small matter of the Premier League's unpredictable nature with United facing a reminder of the uncertainties of this division on Monday, when they face Wigan at the DW Stadium, the scene of a surprising defeat last season which marked a significant turning point in their unsuccessful title bid. "I remember last year we lost 1-0 at Wigan and we showed nothing," said Evra. "It was a really bad performance for Manchester United. This year there will be no excuse. We will just go there, play like Man United and make sure we get the three points because it's really important we do that. I think we have to use the bad experiences we had last year."
If Evra needs to use such memories to inspire him, Ferguson, certainly, is demonstrating no reduction in his desire and resolve to win as he marks his 71st birthday today. West Brom manager Steve Clarke, enjoying a hugely impressive first season in management, was just the latest to marvel at his opponent's longevity and enthusiasm.
"I have met a few grumpy 70-year-olds. He is a typical grumpy Scot," joked Clarke. "He likes to go chasing. He hasn't lost his hunger or his desire. I worked with Sir Bobby Robson at a similar age and he was maybe not quite as aggressive but he was the same. he had that determination and will to win. It is great to see."
Clarke could leave Old Trafford with head held high after his team's performance. United needed a deflection off Gareth McAuley, from an Ashley Young cross, and an injury-time effort from Robin van Persie to see off the visitors for whom 19-year-old midfielder George Thorne ensured a Christmas to remember when, having been recalled from loan at Peterborough, he followed a Boxing Day Championship outing at Wolves with his second Premier League start.
"I had a phone call about 48 hours before the game, as I was preparing to face Bristol City, and they said they needed me in the squad at Old Trafford," said Thorne. "It is a dream of every kid when they're growing up but you can't really get caught up in it. We're here to do a job and unfortunately that didn't happen."