Manchester City won the WSL title impressively last season but externally, there was an expectation Chelsea would bounce back.
Bompastor was more cautious, insisting they were still transitioning after the departures of big-name players including Sam Kerr, Millie Bright and Guro Reiten.
She said: “You need to consider the fact that Chelsea had the same coach for 12 years. It takes a while for players to adjust to a new coach, a new way of playing and a philosophy.
“Even if you have really good players, it doesn’t just go like this. There are a lot of things we are doing behind the scenes for us to stay successful.
“I was lucky enough to come in when [Hayes] left the team in a really good place. But last season we had a year where a lot of important players left.”
But captain Erin Cuthbert said she was “not really” surprised at how good their level has been so far.
“We had a good time to build in pre-season and a good trip away. The quality was always there, we just weren’t clicking,” she added.
“Manchester City ran away with the league in the end, but we were there or thereabouts. I feel this time the team’s just gone up another level.”
As well as adapting more to Bompastor’s ways, and adding defensive solidity to a creative frontline, work has gone into improving the club’s culture.
Cuthbert said before Wednesday’s win there was “really good momentum and a good feeling” in the squad – so can they kick on now?
“For me, the mental aspects and cultural aspects are just as important,” admitted Bompastor.
“We probably needed to rebuild a little bit of that going into this new season. We reflected a lot on how we wanted to set up the process for that.
“Right now, we are in a good place. When you are able to get good results, it’s not only about the tactical aspects. It also has to be about mentality, culture and values.
“I think we have clarity on where we want to go as a team and how we want to get there, and that’s just as important.”