With the transfer window closed, which of the title contenders are now in the best shape to win the Premier League?
The teams aiming for top spot have spent huge sums this summer with some stellar names recruited.
In Manchester, United broke the world transfer record to bring in Paul Pogba, along with Eric Bailly, Henrikh Mkhitaryan and free agent Zlatan Ibrahimovic, while Pep Guardiola added John Stones, Nolito, Claudio Bravo, Ilkay Gundogan, Leroy Sane and Gabriel Jesus to his squad.
There were significant outlays in London, too, with Chelsea making a Deadline Day swoop for David Luiz, after previously signing N'Golo Kante and Michy Batshuayi, while Arsenal will hope to have solved long-standing issues with centre-backs Rob Holding and Shkodran Mustafi, midfielder Granit Xhaka and forward Lucas Perez. Tottenham, meanwhile, signed Vincent Janssen, Victor Wanyama, Georges-Kevin N'koudou and Moussa Sissoko.
Not to be left out, defending champions Leicester brought in relative unknowns Nampalys Mendy, Ahmed Musa, Bartosz Kapustka and Islam Slimani, while Liverpool invested in Sadio Mane, Joel Matip, Georginio Wijnaldum, among others.
But which of the pre-season title favourites has strengthened their squad best during the window? And how has that altered their hopes of lifting the Premier League trophy in May?
We asked Soccer Saturday expert Charlie Nicholas for his assessment - and he believes Arsene Wenger's late moves have propelled Arsenal back into the mix, while he is uncertain on some of Spurs' moves...
"I think the team that needed to do business more than anyone else was Arsenal and Arsene Wenger has successfully identified the two areas, positions I've been on about for five years, and signed a centre-back and a striker.
"Unfortunately, they now start five points behind but it's time for Arsenal fans to move on and be positive again because they've come out this transfer window with a squad capable of challenging the Manchester clubs.
"Both City and United got their transfers done early and you'd probably have to say United did the best business in terms of balance as Jose Mourinho went out and added to each area of his team, while Pep Guardiola has started to impose his vision on City.
"As for Chelsea, I'm not really impressed with what they've done and they haven't really been convincing so far. They're still relying on Eden Hazard performing and Diego Costa not getting sent off.
"They surprised everyone by going back in for the loose cannon David Luiz and I can only think that Antonio Conte sees a problem with Gary Cahill and John Terry to do that deal, because Luiz doesn't seem like his sort of player.
"I also think Spurs are mad spending £30m on Sissoko but they wanted some bodies in. Mauricio Pochettino hasn't strengthened a lot and Daniel Levy, who is usually a tough negotiator, got a bit caught out with having to pay that amount of money.
"I do wonder where Sissoko will fit in as well. Does Erik Lamela or Christian Eriksen miss out? Or does one of the central-midfielders get sacrificed? Because surely they haven't spent £30m on a player who is going to sit on the bench.
"Another puzzler is what's going on at Leicester. I can't actually work out what they are trying to do. They signed Ahmed Musa and now they've signed another striker from Sporting, when they've already got Jamie Vardy and Shinji Okazaki.
"It felt like the owners had taken over the transfer dealings on Deadline Day and flexed their financial muscles while Claudio Ranieri slipped away.
"In the meantime there was nothing happening at Liverpool, leaving James Milner and Alberto Moreno as their left-back options. They're obviously very strong going forward but there's always a mistake in Simon Mignolet and I did think they'd add a really top quality central-defender."