Roberto Mancini said he blamed himself after Manchester City slumped to defeat at Everton, blowing the Premier League title race wide open.
The Italian manager suggested he had not prepared his team properly, with defeat meaning City only remain top of the table on goal difference.
Darron Gibson scored his first goal for the Toffees since his move from Manchester United, when his drive deflected in off of City's Gareth Barry.
David Moyes was delighted on what was already great day for Everton, with the club boosted by the signings of Nikica Jelavic of Steven Pienaar.
United moved level on points with City following their 2-0 win over Stoke, with goals from Javier Hernandez and Dimitar Berbatov.
Elsewhere, Liverpool moved up to fifth after victory at Wolves, while Spurs tightened their grip on third with a win over Wigan.
Tottenham were busy on deadline day, with surprise moves for Everton striker Louis Saha and Blackburn defender Ryan Nelsen.
Vedran Corluka, Sebastian Bassong and Steven Pienaar went out on loan, while Roman Pavlyuchenko looks set to return to Russia.
Anzhi Makhachkala are being linked with Andrey Arshavin, with the Russian transfer window open for another three weeks. (Sky Sports)
Finally, Carlos Tevez remains a City player despite AC Milan's interest, while Pep Guardiola rejected the chance to sign the Argentine. (The Mirror)