The Blues got themselves back in the game after Raheem Sterling cancelled out Alexander Isak's opener with a sublime free-kick to make it 1-1.
But the home side ran away with the game in the second half, with Jamaal Lascelles, Joelinton and Anthony Gordon all getting on the scoresheet as the Magpies sealed a 4-1 win.
Chelsea also found themselves a man down with 15 minutes to go, as captain Reece James picked up a second yellow to sum up a torrid afternoon in the North East.
But Pochettino wasn't going to let his side's performance slide, as he came out and criticised them to the media following the defeat.
Speaking to talkSPORT after the game, he said: "Even in the first half I was disappointed with the performance because we should be better.
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"But the second half we started well, we created a few chances and then when score and then when you concede an easy like the one we conceded, we have to blame ourselves.
"Newcastle wasn't great, I think it was easy for them to win the game."
When asked if he was disappointed by Chelsea's inability to match Newcastle's intensity, he gave a nod to the travelling supporters.
"Disappointing," the Argentine stated. "I'm very sorry even for our fans that were here, they don't deserve this type of performance.
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"We can make mistakes but I think we need to compete better. It was so easy for them to score goals and for us to concede in this way is a little bit of a shame."
Pochettino also alluded to some members of his squad's inexperience not being an excuse for Saturday's performance.
Post-match press conference: Mauricio Pochettino (Premier League: Newcastle 4-1 Chelsea)
He told Premier League Productions: "It was our worst game of the season. It was tough to be in the stands [for three yellow cards this season].
"We cannot complain about the result, we did not read the game from the beginning. We did not play how we should play, we showed a lack of intensity and energy.
"Even after we scored, at 1-1, it was a chance for us to force them to play deep, but it was so easy for Newcastle. That is why I am so upset with the performance.
"It is a young team, they need this type of situation to realise. We will go to the hotel, then train early tomorrow, no time off.
"We cannot blame the players, it is the team together. We need to understand the level we need to compete, and learn about this situation."
Chelsea are 11th in the top-flight, six points off the top six, meanwhile, Newcastle move up to sixth.