Manchester United signed Sofyan Amrabat on loan as part of a hat-trick of arrivals at Old Trafford in the hectic final hours before Friday's transfer deadline, while Liverpool reportedly turned down a £150 million ($190 million) offer from Saudi Arabia for Mohamed Salah.
Manchester City swooped for Wolves midfielder Matheus Nunes in a £53 million deal after selling Cole Palmer to Chelsea and Tottenham landed Brennan Johnson from Nottingham Forest in the day's other major deals.
English top-flight clubs smashed their record for spending on new players during this window, with the total surpassing £2 billion for the first time, according to financial experts Deloitte.
"You've got that intensity of competition across the league. Whether that's competing for the title, competing for European places or just simply staying in the league, that's driving spending," said Calum Ross, assistant director in Deloitte's Sports Business Group.
"There are 10 clubs that have spent more than £100 million."
United left it late to get a deal done for midfielder Amrabat that will see one of the stars of Morocco's run to the World Cup semi-finals join from Fiorentina for a 10 million euro (£8.6 million) loan fee with the option to buy for a further 25 million euros next year.
Amrabat was joined by Turkish goalkeeper Altay Bayindir from Fenerbahce and Spanish left-back Sergio Reguilon, who was with Spurs, in joining the Red Devils on deadline day.
"I've had to be patient for this moment but I'm someone who always listens to my heart and now I am representing the club of my dreams," said Amrabat in a United statement.
Mason Greenwood departed United on Friday, joining Spanish side Getafe on loan.
The club and Greenwood mutually agreed for the forward to continue his career elsewhere after he faced allegations of abuse involving a young woman.
Liverpool completed their midfield overhaul with the signing of Ryan Gravenberch from Bayern Munich in a £35 million deal.
But the Reds stood firm in the face of Al-Ittihad's attempt to lure Salah to Saudi.
"The position remains the same. Absolutely no doubt about that," Liverpool boss Jurgen Klopp said of the Reds' desire to keep the 31-year-old, who has two years left to run on his contract.
However, the Saudi transfer window does not close until September 7.
Treble winners City bolstered their midfield options after the departure of Ilkay Gundogan and a long-term hamstring injury suffered by Kevin De Bruyne by signing Portugal international Nunes.
"The opportunity to work under Pep Guardiola, one of the greatest managers ever, and alongside some of the best players in the world was something I simply couldn't turn down," said Nunes.
City cashed in on Palmer for an initial £40 million that takes Chelsea's spending on new players in just over a year under the club's American ownership beyond £1 billion.
Tottenham splashed out some of their Harry Kane cash on Johnson for a £47.5 million fee.
Brighton landed a major coup by signing Spanish international winger Ansu Fati on a season-long loan deal from Barcelona.
Paris Saint-Germain announced the signing of France striker Randal Kolo Muani from German club Eintracht Frankfurt early on Saturday, moments after the summer transfer window closed in Europe.
Kolo Muani has signed a five-year contract with the Ligue 1 champions, after media reports in France said they had agreed to pay a fee totalling 90 million euros ($97m) to Frankfurt.