Atalanta definitely doesn't look like they are a great team this season, and yet they somehow managed to get a good win here. It was a very boring game aside from the three goals

. I know that sounds very crazy when you hear about it, but Atalanta seriously just held the ball, didn't even passed it around that much, just didn't "do" anything, cooled the game down, and just as Juventus lost focus when Atalanta was doing nothing, suddenly Atalanta started to attack quickly, and repeated this. It really worked great for them.
That's literally what Italian football is about haha. They have been infamous for this. Focusing on defence and destruction rather than pressing for more goals.
I've just watched the highlights of that game. Juventus started off really well, putting a lot of pressure on Atalanta. They had like 3 good scoring chances but couldn't convert any of them into goal. Then that handball happened and a penalty for Atalanta. After taking the lead, they could just focus on defence. They pressed a bit towards the end of the game, creating two chances and turning both of them into goals.
Not the prettiest performance, but I'm sure Atalanta's fans are not complaining.