Manchester United's title challenge suffered another blow with a heavy defeat at Newcastle.
The visitors, who lost to Blackburn on New Year's Eve, went behind before the break when striker Demba Ba hooked in his 15th goal of the season.
Yohan Cabaye doubled Newcastle's lead with a 30-yard free-kick before Phil Jones diverted in a late own goal.
Wayne Rooney had a shot blocked on the line and Dimitar Berbatov's header hit the post for the champions.
The Jones howler, which came deep in stoppage time, summed up Manchester United's night at the Sports Direct Arena.
Visiting manager Sir Alex Ferguson said prior to the match that his side may be affected by the strong winds - and they indeed failed to cope in the difficult conditions as Alan Pardew's Newcastle thrived.
But the champions were also slow to the loose ball and ineffective in attack. The defeat leaves them three points behind fierce local rivals Manchester City, who beat Liverpool 3-0 on Tuesday.
With Tottenham breathing down their necks, Ferguson will need to call upon all his great managerial experience to lift his players after two successive league defeats.
This was arguably his side's worst performance of the season, but the Magpies deserve credit because they were faster, stronger and sharper.
The home side won the key battles in the middle, while Manchester United centre-backs Rio Ferdinand and Phil Jones failed to cope with the muscle of strikers Ba and Shola Ameobi when the ball was pitched up.
At the other end of the field, Rooney and Berbatov were given little space by the Newcastle back four, with defensive midfielder Cheick Tiote producing another tireless performance as back-up.
The game may have turned out differently had Berbatov capitalised on Antonio Valencia's cross with the score goalless but his deflected header struck the base of Tim Krul's right-hand upright.
Manchester United's only other clear chance fell to Rooney, whose strike from four yards was blocked by Newcastle right-back Danny Simpson to preserve the home side's 2-0 lead.
Apart from those efforts, the Old Trafford side struggled to create. Nani occasionally delivered a dangerous ball, but the front two were often found dropping deep in order to bring themselves into the game.
For Newcastle manager Pardew, he will enjoy what is undoubtedly one of the best results of his managerial career.
His side took the lead in the first half when Ba picked up a flick from partner Ameobi and then hooked his shot past Anders Lindegaard, who conceded only his second goal in eight appearances.
Two minutes after the break, the Magpies extended the lead with one of the strikes of the season when France midfielder Cabaye curled in a 30-yard free-kick which bounced in off the underside of the bar.
The visitors' night came to a calamitous conclusion when keeper Krul's long punt downfield was misjudged by Jones, who diverted the ball into the net.