Liverpool crashed to an embarrassing 2-0 defeat at Burnley on Saturday, while Manchester City crushed Stoke City 4-1 to extend Pep Guardiola's perfect start in the Premier League.
While Liverpool stumbled and City strolled, champions Leicester City are still awaiting the first win of their title defence after being held to a 0-0 draw by Arsenal.
Jurgen Klopp's Liverpool enjoyed the most eye-catching result of the Premier League's opening weekend when they won 4-3 at Arsenal.
But the Reds suffered a nightmare in their second match as Welsh forward Sam Vokes scored his first top-flight goal in the second minute after Andre Gray pounced on a woeful pass by Reds right-back Nathaniel Clyne.
Liverpool were condemned to a first league loss at Turf Moor since 1973 when Gray ran onto Steven Defour's pass and punished slack marking to fire home in the 37th minute.
"How can I be happy with this? After we gave away the first goal Burnley defended for their lives," Klopp said.
"We had absolutely no luck and everybody needs to be more clinical. Burnley deserved to win with a very passionate performance. We have to say it was not enough today."
At Stoke's Bet365 Stadium, City striker Sergio Aguero netted twice in the first half to take his goal tally to six in three games and send Guardiola's side to the top of the table with their second successive win.
The Argentine opened the scoring with a 27th-minute penalty, awarded for a Ryan Shawcross tug on Nicolas Otamendi, and bagged his second in the 36th minute with a header from Kevin De Bruyne's free-kick.
Stoke got one back in the 49th minute when Raheem Sterling was penalised for a slight push on Shawcross and Bojan Krkic stepped up to convert the spot-kick.
But the visitors held firm and Spain forward Nolito scored with a pair of close-range efforts in the 86th and 90th minutes to give City manager Guardiola a third consecutive victory in all competitions.
"I'm really impressed with the players as human beings and with their performance," former Bayern Munich and Barcelona boss Guardiola said.
"We have only had one month together. There is time to get better."
City's romp in the Potteries took them above arch rivals Manchester United, who defeated Southampton 2-0 on Friday.
At the King Power Stadium, Leicester, beaten by Hull City last weekend, saw two penalty appeals turned down by referee Mark Clattenburg -- first when Laurent Koscielny stretched to tackle Danny Drinkwater, then when Ahmed Musa was challenged by Hector Bellerin.
To cap a frustrating day, Leicester boss Claudio Ranieri also saw French midfielder Nampalys Mendy forced off with a second-half injury.
Asked about the penalty controversy, Ranieri said: "My philosophy is it's a penalty when the referee blows his whistle and that's it. The manager makes mistakes, the referees make mistakes."
Gunners boss Arsene Wenger added: "It was a game of top-level intensity and I believe we responded well to last week's disappointment."
Fortunate
Diego Costa fired Chelsea to another late victory as the Spain striker secured a 2-1 win at Watford just days after his last-gasp heroics saw off West Ham.
Etienne Capoue broke the deadlock in the 55th minute when Watford's French midfielder lashed his shot into the top corner from Adlene Guedioura's cross.
But Chelsea striker Michy Batshuayi came off the bench to equalise for Antonio Conte's side in the 80th minute after Heurelho Gomes weakly parried Eden Hazard's shot.
Batshuayi's first goal since his pre-season move from Marseille sparked Chelsea into life and Costa, fortunate to still be on the pitch after avoiding a second booking for diving, rifled in from a Cesc Fabregas assist in the 87th minute.
Kenya midfielder Victor Wanyama scored his first goal for Tottenham Hotspur to clinch a 1-0 win over Crystal Palace at White Hart Lane.
Wanyama, a summer signing from Southampton, headed home from close-range in the 83rd minute after Harry Kane flicked a corner in his direction to give Tottenham their first victory of the season and leave Palace pointless.
Gareth Barry's first goal since January 2014 gave Everton a 2-1 victory at West Bromwich Albion.
Albion took an early lead through Gareth McAuley, but equalised through Kevin Mirallas in first-half stoppage time and former England midfielder Barry headed the 60th-minute winner.
Troubled Hull continued to make light of their difficult pre-season with a 2-0 win at Swansea City as late goals from Shaun Maloney and Abel Hernandez lifted them to third.