James Henry gave the home side the lead before a late Steve Morison double saw off Scunthorpe 3-0, lifting Millwall into the top half of the table.
Jackett said: "First and foremost it was a good result for the team and we are pleased with that.
"We have had quite a few chances in the last few weeks and not taken them, so to have a lot and take a few of them was really pleasing."
He continued: "What was also pleasing was that we did really well defensively and limited them to a few chances, which was really good for us.
"However, I felt in between the two boxes we weren't as good as we could be though so there is definitely something to work on. That was a little bit disappointing and is definitely something we need to improve - but otherwise I was pleased."
Source: PA
Source: PA