LONDON — Manchester City needed a 90th minute winner to beat Crystal Palace 1-0 and secure a fifth consecutive victory this season, while Premier League champion Chelsea slumped to a 3-1 defeat at Everton on a day of contrasts for title hopefuls.

Kelechi Iheanacho came off the bench in the 89th and poked the ball into the Palace net a minute later, as City maintained its perfect start to the season on Saturday.

But if things couldn’t have ended much better for City, they couldn’t have gone much worse for Chelsea, which was torn apart by Everton’s hat-trick scorer Steven Naismith.

While City has earned 15 points so far, Chelsea has managed just four in its title defence.

In other matches, Arsenal missed a host of chances in a 2-0 win over Stoke, Norwich beat Bournemouth 3-1 and Watford edged Swansea 1-0. West Brom drew 0-0 at home to Southampton.

Manchester United hosts Liverpool, one of English soccer’s showcase fixtures, in the late kickoff at Old Trafford.

United’s neighbours were made to work hard for their victory in London against a Palace side that has made an excellent start to the season.

City’s saviour was the unheralded teenager Iheanacho, who played on the club’s U.S. tour in the summer.

The 18-year-old Nigerian had only played competitively for City once before, and that too was as an 89th minute substitute – against Watford in August.

“It means so much to me,” he told the City website. “I’m happy and very grateful and I thank the manager for introducing me.”

Saturday’s game also witnessed a promising debut for club record signing Kevin de Bruyne from the bench, albeit after striker Sergio Aguero left the pitch with a worrying injury.

Off the field, there was a mild altercation between the two managers following Yaya Toure’s late tackle on Palace’s James McArthur, with City’s Manuel Pellegrini tugging back Alan Pardew.

There was more than just frustration, though, for Chelsea manager Jose Mourinho after his side was convincingly beaten at Goodison Park.

Having come on as a ninth-minute substitute for the injured Muhamed Besic, Naismith headed Everton into a 17th-minute lead and quickly followed up by scoring his second with a low drive from outside the area.

Nemanja Matic pulled a goal back for Chelsea with a long-distance effort in the 36th but Naismith put the result beyond doubt by squeezing an angled shot through the legs of goalkeeper Asmir Begovic in the 82nd.

Mourinho was defiant about his side’s latest result, and his own position.

“I don’t think there is a better manager than me to come to Chelsea and to do my job. That’s so simple as that. I’m the man for the job,” he told BT Sport.

Despite what he described as “the worst results ever in my career”, Mourinho was convinced that Chelsea’s fortunes will change and that his players are just having a run of bad luck.

“The way they are playing is not so bad as the results,” he said. “But in every game everything goes against (us) … The priority is to keep doing what we are doing,” he insisted.

“I cannot put more pressure on the players — the players are feeling enough sadness and enough frustration, and lack of confidence.”

If Chelsea struggled, Arsenal dominated Stoke at Emirates Stadium and could easily have won by a tennis score.

Instead, just two goals from strikers Theo Walcott and Olivier Giroud sealed the points.

Walcott broke the deadlock in the 31st minute after running onto a perfect through ball from Mesut Ozil, and Giroud came on as a substitute to put the result beyond doubt in the 85th.

Watford won its first league match of the season, despite being reduced to 10 men.

Nigeria striker Odion Ighalo scored in the 59th minute with a shot into the bottom left corner. Watford went a man down less than five minutes later when Valon Behrami was sent off for a violent tackle on Andre Ayew.

Wes Hoolahan inspired Norwich to a comfortable first home league win of the season, making one goal and scoring another in the victory over Bournemouth.

Trevor Huggins, The Associated Press