After another transfer window of wheeler-dealing, BBC Sport's chief football writer Phil McNulty analyses the winners and losers as the Premier League clubs brace themselves for the season run-in:
Key moves in: Juan Mata [from Chelsea] £37.1m.
Key moves out: Fabio [to Cardiff] undisclosed, Larnell Cole and Ryan Tunnicliffe [to Fulham] undisclosed, Anderson [to Fiorentina] loan, Jack Barmby [to Hartlepool] loan, Wilfried Zaha [to Cardiff] loan, Sam Byrne & Charni Ekangamene [to Carlisle] loan, Tyler Blackett, Tom Thorpe & Federico Macheda [to Birmingham] loan, Tom Lawrence [to Yeovil] loan, Sam Johnstone [to Doncaster] loan, Will Keane [to QPR] loan.
Manchester United manager David Moyes went for quality not quantity in January. One signing. One high-class player in Juan Mata at a club-record fee of £37m from Chelsea.
Mata may not solve United's major problems - a creaking defence and a midfield short of a world-class player - but his arrival has changed the mood at Old Trafford and proved Moyes and chief executive Ed Woodward can get the big deals over the line.
He could be a game-changer, not in the context of retaining their title but by lifting United's hopes of making the top four and securing a place in next season's Champions League - unless they win this season's competition, of course.
Key moves in: Konstantinos Mitroglou [from Olympiakos] £11m, Larnell Cole and Ryan Tunnicliffe [from Manchester United] undisclosed, John Heitinga [from Everton] free, Clint Dempsey [from Seattle Sounders] loan, William Kvist [from Stuttgart] loan, Lewis Holtby [from Tottenham] loan.
Key moves out: Philippe Senderos [to Valencia] undisclosed, Bryan Ruiz [to PSV Eindhoven] loan, Stephen Arthurworrey [to Tranmere] loan, Marcus Bettinelli [to Accrington] loan, Jack Grimmer [to Port Vale] loan, Aaron Hughes [to QPR] free, Dimitar Berbatov [to Monaco] loan, Adel Taarabt loan terminated.
This was a big window for Fulham and new boss Rene Meulensteen - and early impressions look good after a very busy month in the market.
The departure of Dimitar Berbatov has been offset by the £11m signing of Olympiakos striker Konstantinos Mitroglou, while the loan deal for Tottenham's Lewis Holtby means they have secured a player who was coveted during his career in the Bundesliga with Schalke before moving to White Hart Lane.
Clint Dempsey's return and the signing of Netherlands defender John Heitinga from Everton add valuable experience.
Fulham needed to take action after sliding down to 19th in the Premier League - and Meulensteen will believe this hectic spell of business will bolster their hopes of staying in the top flight.
Key moves in: Wayne Hennessey [from Wolves] £3m, Jason Puncheon [from Southampton] undisclosed, Scott Dann [from Blackburn] undisclosed, Joe Ledley [from Celtic] undisclosed, Thomas Ince [from Blackpool] loan.
Key moves out: Jason Banton [to Plymouth] undisclosed, Matt Parsons [to Plymouth] undisclosed, Kevin Phillips [to Leicester] free, Jimmy Kebe [to Leeds] loan, Kwesi Appiah [to Notts County] loan, Stephen Dobbie [to Blackpool] loan.
Tony Pulis has revived the Selhurst Park club since his appointment as manager and he has built on that good work in the January transfer window, especially in those hectic final hours.
Pulis wanted to strengthen his squad this month, and chairman Steve Parish delivered on the final day.
He will feel he has acquired a player of real promise in Tom Ince from Blackpool while Scott Dann is an experienced, battle-hardened defender. Joe Ledley will add quality and experience in midfield and there was even time to sign goalkeeper Wayne Hennessey from Wolves for £3m and Jason Puncheon, so prominent recently, on a permanent deal.
Pulis has made Palace tough to beat, secured vital wins and has now fleshed out his squad shrewdly for the crucial months ahead.
Key moves in: Kim Kallstrom [from Spartak Moscow) loan.
Key moves out: Nico Yennaris [to Brentford] undisclosed, Emmanuel Frimpong [to Barnsley] undisclosed, Chuba Akpom [to Brentford] loan, Anthony Jeffrey [to Wycombe] free, Benik Afobe [to Sheffield Wednesday] loan, Park Chu-young [to Watford] loan.
Arsenal manager Arsene Wenger decided against making a big January signing - and the wisdom of his decision to keep his powder dry will be judged at the end of the season.
Wenger's only deal was to bring in Spartak Moscow's experienced Swedish midfield man Kim Kallstrom on loan after deciding not to press on with a deal for Schalke's Julian Draxler.
Perhaps Wenger's biggest gamble has been his decision not to bring in a striker, even on loan, to add to attacking resources that look vulnerable to injuries.
Wenger has cast-iron faith in his Arsenal squad but they have a fierce programme ahead in the Premier League, Champions League and FA Cup. Has he left himself short?
Key moves in: Luuk de Jong [from Borussia Monchengladbach] loan.
The biggest losers of all in the transfer window - with a lack of activity that is bound to raise further questions about the role of director of football Joe Kinnear.
On the surface, Kinnear's job appears to be to do the deals and bring players in to Tyneside. If this is the case, he has hardly been a success.
Yohan Cabaye left for Paris St-Germain in a £19m deal but there was no midfield replacement for such an influential player, with Borussia Monchengladbach striker Luuk de Jong the only incoming.
This leaves Newcastle manager Alan Pardew in a weakened position despite his hopes of bringing a player in to fill the vacancy left behind by Cabaye.
If Newcastle's season fades, there are likely to be repercussions from fans who will be very unhappy at a failure to significantly strengthen the squad while in a decent Premier League position.
Key moves in: None.
Liverpool's month of frustration was encapsulated in the final moments of the window when the £15m deal to sign FC Dnipro forward Yevhen Konoplyanka could not be completed.
Managing director Ian Ayre flew to Ukraine to try and secure the "major signing" manager Brendan Rodgers wanted as the Reds continue their push for a place in the Premier League top four.
The fact he will return empty-handed will be a source of real disappointment for Liverpool and their fans, especially after seeing Mohamed Salah move to Chelsea in an £11m deal after he emerged as a top target for Rodgers.
It seems the Konoplyanka deal fell through when Dnipro did not sign off the relevant paperwork, and Rodgers must now press ahead with the squad that has served him well and hope an unsuccessful January transfer window does not impact on the rest of their season.
And the rest...
Cardiff City's new manager Ole Gunnar Solskjaer needed to act urgently as they are bottom of the Premier League - and he is relying heavily on former club Manchester United for help.
He will hope the loan deal for Wilfried Zaha provides some firepower, along with the recruitment of Kenwyne Jones from Stoke City, while Fabio's arrival from Old Trafford will add to his defensive strength.
And it remains to be seen how successful his return to another former club, Molde, where he was manager, for Mats Moller Daehli and Jo Inge Berget will be. There is a huge element of a gamble - and the price of failure will be expensive.
Chelsea manager Jose Mourinho was a big dealer in and out. Nemanja Matic, returning to Stamford Bridge in a £21m deal from Benfica, will add power and stability in central midfield but there are still plenty of Chelsea fans who will worry they may yet miss the creativity of the popular Juan Mata after his move to Manchester United.
Another manager working the markets heavily was West Ham's Sam Allardyce as he attempted to recover from the initial disappointment of losing out on Monaco striker Lacina Traore to Everton in a loan deal.
Allardyce will hope Roma striker Marco Boriello and AC Milan midfield man Antonio Nocerino - both Italy internationals - add goals and creativity, commodities sorely missed this season.
And so to the Premier League leaders Manchester City.
They pondered a double deal for Porto pair Eliaquim Mangala and Fernando but in the end pulled back, although both remain transfer targets and may be revisited this summer.
City worked strategically in the close season to build a squad for the whole campaign for manager Manuel Pellegrini. He has decided to leave well alone. And who can blame him after their magnificent recent form?