Manchester City manager Manuel Pellegrini says his side must take every game like a cup final for the rest of the season after being hammered 4-1 at Tottenham.
City started the brighter and forced Hugo Lloris into a couple of saves before Kevin De Bruyne broke free and hammered a low shot home to give them the lead, despite a questionable offside call.
But Tottenham hit back with four goals -- two of which may not have stood if offside players been spotted by referee Mark Clattenburg's assistants -- and left Pellegrini unhappy with the performance.
"We didn't play very well in the first half against West Ham, or in the second half here," he told BT Sport. "I don't want to talk about the goals because it's a mistake, the referee can make it.
"We must continue working, to continue playing as we did in the first 45 minutes. We must play every game as a final in the future."
Toby Alderweireld and Harry Kane scored after a corner and free-kick respectively, and Pellegrini was angry about the defending.
"In the second half it was two set-pieces, one decides the game, but after that they played very well," he added. "We defended some balls very badly. Two set-pieces, two goals."
The result moved Spurs within three points of Man City and afterwards talk quickly turned to a top-four tilt.
"We need to keep calm, like the shirt," Pochettino said. "In Spain, a lot of the kids have 'keep calm', 'keep calm' on their t-shirts.
"This is true because we are very young. Now after three victories in a row in the Premier League, it is very important for us.
"It is important for them to believe in the way that we play and our philosophy of how we do our job, but remain calm because it is only the beginning of the season and nothing has happened yet.
"We have a long way ahead. We are very young and sometimes we can confuse quick."
As well as joy, there was a palpable air of relief around White Hart Lane when fans' favourite Kane netted. The England international has struggled to scale the heights he achieved during his exquisite breakthrough season, but his reaction strike after Christian Eriksen hit the bar ended a long, frustrating drought.
"It is very important for him, very important for us to help the team," Pochettino said. "I think it was great for him to take off the pressure."
Midfielder Yaya Toure was taken off after 56 minutes and Pellegrini revealed: "There was a problem with his hamstring, he couldn't train during the week."