Arsene Wenger has challenged his young Arsenal side to show their true title credentials at Chelsea next weekend after being handed a masterclass by Manchester United.
The Gunners are now some five points off the pace following yesterday's 3-0 home defeat against a rampant Red Devils.
That gap could be up to eight by the time they head to Stamford Bridge should, as expected, Chelsea beat Hull in their rearranged midweek fixture.
After a reasonable start, Arsenal were soon pushed on the back foot in front of their own frustrated fans as United took the lead when Portuguese winger Nani saw his chip across goal palmed in by Arsenal goalkeeper Manuel Almunia, before in-form England striker Wayne Rooney swept home a second following a clinical counter-attack.
A third on the break from Park Ji-Sung at the start of the second half effectively ended the contest, although defender Thomas Vermaelen netted a consolation for the outmuscled Gunners.
It was a similar disappointing display as the home encounter with Chelsea at the end of November, after which a fine run of seven wins in nine league games had hauled the young Gunners right back into the title race.
Wenger knows it will take another Herculean effort to turn Arsenal's season once again.
"It is a massive blow and a massive disappointment," he said, "We need something special now to stay in the race, of course. I am conscious of that.
"But we have to recover, that is part of top-level football.
"It is difficult to take, but easy to explain because we were poor offensively and defensively.
"We delivered an off-the-mark performance completely and that is why we were well beaten.
"We gave them always too much room, we were naive. They were better than us for two reasons: one, they played well and two, we were not at our level.
"Why? It is too early to analyse that. I believe there are some mental reasons in there, but it is difficult to say.
"Now, we have to stick together, recover and produce a much better performance next Sunday [against Chelsea]."
Arsenal have certainly missed the presence of Holland international Robin van Persie since the forward was ruled out until April with an ankle injury.
Wenger, though, maintains he is unlikely to look for a quick fix by dipping into the market ahead of the transfer deadline.
"We are not on any business before Monday evening," the Gunners boss insisted.
