David Luiz. Photograph:( AFP )
Manchester United striker Romelu Lukaku's prolonged transfer to Inter Milan was also completed after the clubs reportedly agreed on a deal
Tottenham led the way on a busy final day of the Premier League transfer window with deals for Giovani Lo Celso and Ryan Sessegnon, while Arsenal strengthened their defence with the signings of Kieran Tierney and David Luiz.
Manchester United striker Romelu Lukaku's prolonged transfer to Inter Milan was also completed after the clubs reportedly agreed on a deal that could rise to €80 million (£74 million, $90 million).
Spurs chairman Daniel Levy has been under pressure from manager Mauricio Pochettino to build on the progress made on and off the field as Tottenham moved into a new 62,000-capacity stadium and reached the Champions League final last season.
After the club-record signing of French international midfielder Tanguy Ndombele, the signings of Lo Celso and Sessegnon add some much-needed depth to a Spurs squad that had previously gone 18 months without a new recruit.
Argentine international midfielder Lo Celso has joined on a season-long loan deal from Real Betis with an option to make the transfer permanent next summer.
England under-21 international Sessegnon joins from Fulham in a £25 million deal that could rise to £30 million in performance-related add-ons on a six-year contract.
"I think it is the right time for me to come here," said Sessegnon. "It's a young, eager, exciting team for me to join and I think this team is not far off winning big things in the future."
However, a sensational swoop for Juventus' Paulo Dybala broke down, leaving Spurs short on support for Harry Kane up front.
Arsenal bolster defence
Arsenal were badly in need of defensive recruits to shore up a backline that conceded 51 Premier League goals last season to miss out on Champions League football for a third straight year.
The Londoners' long-standing interest in Tierney was finally given the green light when the payment structure of a £25-million move was agreed with Celtic.
"I've lived my dream and I've loved every single minute of it," said Tierney of leaving his boyhood club. "Now I just feel was the right time to take a step on. I feel this is a great opportunity for me."
Arsenal then secured some much-needed cover at centre-back in an £8 million deal for Luiz.
"David has huge experience and I look forward to working with him again. He is a well known player and adds to our defensive strength," said Arsenal boss Unai Emery.
The Gunners clawed back that deadline day spend after agreeing a £35 million deal to sell Nigerian international striker Alex Iwobi to Everton.
Iwobi is Everton's seventh signing of the summer following goalkeeper Jonas Lossl, right-back Djibril Sidibe, midfielders Andre Gomes, Fabian Delph and Jean-Philippe Gbamin, and striker Moise Kean.
Manchester City and Liverpool are expected to battle for the Premier League title once more, but were not busy on deadline day.
City brought in veteran goalkeeper Scott Carson on loan from Derby as back-up to Ederson and Claudio Bravo after the signings of Rodri, Angelino and Joao Cancelo earlier in the window.
Liverpool made just three low-key additions in teenagers Sepp van den Berg and Harvey Elliott and back-up goalkeeper Adrian over the course of the summer.
Outside the top six, Watford broke their transfer record to bring in Senegal international Ismaila Sarr for a reported €35 million from Rennes.
Wilfried Zaha's hopes of a move from Crystal Palace were snubbed as Everton could not match the London club's asking price.
"It's been well documented that he wanted to leave, but it has not worked out for him," admitted Palace manager Roy Hodgson.
Brighton bolstered their midfield options with the loan signing of Australian international Aaron Mooy.
Former England international Andy Carroll returned to Newcastle on a free transfer from West Ham, while the Magpies also secured Swedish defender Emil Krafth.
Leicester used some of the £80 million they received from Manchester United for Harry Maguire on Sampdoria midfielder Dennis Praet for €20 million.
And Burnley secured the services of Danny Drinkwater on loan from Chelsea until January.