Albion defeated the European champions with goals from man-of-the-match Vicente, Ashley Barnes and the returning Andrew Crofts after falling behind to Frank Lampard's opener.
"I'm very pleased but I don't want to take this as more than it really is," said former Chelsea midfielder Poyet following the game.
"It was a very good game of football against top opposition. We found ourselves for long periods, especially in the second half, without the ball which is new for us. We had to defend, we had to do the ugly part of the game.
"We suffered but the boys did the basics. I'm very pleased for them. It was a difficult game for them.
"When they saw the (Chelsea) team listed in front of them and all the names they started thinking about that, so I'm pleased for them. We started well until the goal, which we conceded too easily. But it was a very good reaction."
