Raul Meireles and Mikel Arteta swapped the city of Liverpool for London in dramatic deals on a busy transfer deadline day.
In a frantic final day of the transfer window, Premier League clubs took their summer spending to £485m, business analysts Deloitte said.
That outlay represents a 33% rise on the same period in 2010, an increase of £120m.
Arsenal also signed Germany defender Per Mertesacker and left-back Andre Santos from Fenerbahce for £6.2m, as Arsene Wenger reshaped his squad after Sunday's 8-2 defeat by Manchester United.
Manchester United did not make any deadline-day deals, with Inter Milan's Wesley Sneijder revealing on Twitter that he would be staying in Italy.
BBC Sport pundit Martin Keown said he has reservations about how many of the late transfers will prove to be successful.
"On the whole, deals involved players with Premier League experience already," he commented. "That indicates what clubs are after at the moment.
"We have got to see how well these deals pan out, of course. You can be sure that a lot of them will not turn out to be successes.
"But I do not think we have had this many late signings in the past and the day really had a feeling of last-chance saloon about it.
"We will also remember this transfer window for the deals that never happened. Despite lots of speculation, Carlos Tevez, Luka Modric and Wesley Sneijder have all stayed where they are - at Manchester City, Spurs and Inter Milan respectively."
One club who looked outside of the Premier League to bolster their attacking options was Fulham, who bought Bryan Ruiz from FC Twente for £10.6m, beating off a late rival bid from Newcastle United. The Cottagers also recruited Orlando Sa for free from Porto.
Spurs also let Jermaine Jenas and Alan Hutton move to Aston Villa, the latter opting for the West Midlands over a move to Fulham.
Tottenham winger David Bentley joined West Ham on a season-long loan.
Spurs completed a deal for West Ham United's Scott Parker, but failed to sign Bolton defender Gary Cahill.
Sunderland ended their search for a striker when Nicklas Bendtner moved from Arsenal on a year-long loan deal.
Arsenal also let young forward Joel Campbell, who only signed last week, join French side Lorient on loan, following team-mate Gilles Sunu, who made a permanent switch to the Ligue 1 outfit.
QPR added Manchester City winger Shaun Wright-Phillips and Sunderland's Anton Ferdinand to their squad. Their move for Spurs defender Sebastien Bassong fell through due to Spurs' failure to sign Cahill.
As well as keeping hold of their prized defensive asset Cahill, Bolton added new faces by sealing a permanent deal for Liverpool striker David Ngog and a loan switch for Chelsea midfielder Gael Kakuta.
Blackburn raided Goodison Park to sign striker Yakubu, and also completed moves for Birmingham defender Scott Dann and Sheffield United frontman Jordan Slew.
Everton made two loan signings: Real Madrid's Royston Drenthe on loan and striker Denis Stracqualursi from Argentine side Tigres. The Toffees let Jermaine Beckford join Leicester.