French striker Olivier Giroud has joined Chelsea from London rivals Arsenal in a deal worth £18m.
He has signed an 18-month contract with the Premier League champions with an option of a further year.
Giroud replaces Belgian forward Michy Batshuayi after the former Olympique Marseille forward joined Borussia Dortmund on a short-term loan as a replacement for new Arsenal player Pierre-Emerick Aubameyang.
Arsenal’s North London rivals Tottenham Hotspur have also strengthened their squad with the capture of Brazilian winger Lucas Moura from French giants Paris Saint Germain (PSG) in a £25m deal.
Another London club in Crystal Palace have a new striker after Alexander Sorloth joined the Eagles from Midtjylland on a four-and-half year deal in a deal reported to be worth £9m.
Swansea City followed up their impressive win over Arsenal at the Liberty Stadium on Tuesday with the double signing of Andre Ayew and Andy King.
Ayew returns to the club to link up with brother Jordan in a deal worth £18m and has signed a three-and-half year deal.
Premier League winner Andy King has also teamed up with Swansea City on a 6-month loan from Leicester City.
West Ham have swiftly replaced Ayew with the signing of forward Jordan Hugill from English Championship side Preston for an undisclosed fee.
Newcastle United have boosted their hopes of beating the drop with the short-term loan signings of French defender Eliaquim Mangala from Manchester City and Algerian striker Islam Slimani from Leicester City.
Stoke City also have a firm target to avoid relegation from the Premier League and that has been boosted by the arrival of midfielder Badou Ndiaye from Galatasaray in a £14m deal.
Bournemouth didn’t make any significant signing on deadline day but they allowed striker Benik Afobe to join English Championship leaders Wolverhampton Wanderers on loan till the end of the season.