By reining in Arsenal at the top of the Premier League table, Manchester United made it clear that they are determined to have a say in this season's title race.
Amid the cut and thrust of the season's formative weeks, the reigning champions had been conspicuous by their absence from the table's upper reaches.
Defeats by Liverpool, West Bromwich Albion and Manchester City -- the latter a crushing 4-1 loss -- left David Moyes's side unable to join in with the jostling for position at the summit.
Arsenal have been the season's stand-out team, with Liverpool and Southampton close behind, but United's sluggish start obliged them to toil in relative obscurity while plaudits were sprinkled on the sides above them.
They have found renewed resolve in recent weeks, avoiding defeat since that stunning reverse at home to West Brom on September 28, but they needed to beat a fellow title contender to prove that reports of their demise had been exaggerated.
Sunday's victory over Arsenal provided exactly that and although Arsene Wenger's side never truly threatened David de Gea's goal at Old Trafford, United were on a tightrope throughout.
Defeat would have left them 11 points off the pace. Instead, victory cut Arsenal's lead over them to just five points, and catapulted Moyes's side back into the top five for the first time since a 2-0 win over Crystal Palace in mid-September.
"We knew we could not afford to lose," said Wayne Rooney. "We couldn't let Arsenal get 11 points away from us."
Moyes claimed that United did not need to make a statement, but after Chelsea's 2-2 draw with West Brom and defeats for both City and Tottenham Hotspur, failure to make ground would have been a huge missed opportunity.
Aside from a trip to Spurs on December 1, United will not face one of their title rivals before the end of the year.
The challenge they now face is to assemble the kind of long winning sequences that are the hallmark of title-winning teams.
They will draw great encouragement from the performances of Rooney and Robin van Persie against Arsenal, which suggested that United have no reason to envy any other strike partnership in the league.
Van Persie's sureness of touch gave United an attacking launchpad throughout the match and Rooney capped a display of breathless endeavour by teeing up the Dutchman for the game's only goal.
The pair now have 17 goals between them in all competitions, while Shinji Kagawa is beginning to demonstrate that he can summon the necessary levels of industry to make an impact in the Premier League.
The emergence of 18-year-old winger Adnan Januzaj has been another plus in attack, even if United have scored 10 fewer league goals than Manuel Pellegrini's entertainers at City.
There is room for improvement at the other end of the pitch, however, despite a disciplined counter-attacking display against Arsenal.
United have only kept three clean sheets in the league, with Moyes's attempts to build the sort of settled defensive unit from which he benefited at Everton hampered by successive injuries to stalwarts Rio Ferdinand and Nemanja Vidic.
Phil Jones's commanding display against Arsenal suggested that he may represent a long-term solution at centre-back, but the inauguration of a new back four will involve a degree of trial and error.
Moyes was keen to underline that his side still have "a few big steps to take" and the season's tumultuous early weeks suggest he is right to exercise caution.
It will be a while before United's fans fully recover from the shock of the hiding at City or the abject loss to West Brom, but victory over a buoyant Arsenal -- coupled with the ongoing state of flux at the top of the table -- gives them hope that a title challenge is taking shape.