After suffering heavy defeats at the hands of Collingwood, Hawthorn and the Western Bulldogs in their past three starts, the Power showed major improvement in the seven-point loss to the Bombers.
They led by 34 points during the last quarter, but were eventually overwhelmed by their stronger-bodied opposition and conceded the last seven goals of the match.
"As disappointed as we are with the loss - we came over here to win - I guess it's a step in the right direction after the month we've had," Cassisi said post-match.
"The group has stuck together well.
"We want to be better, and three-and-a-half quarters isn't good enough, but we think we've taken a small step in the right direction."
Sticking to the same line as his coach Matthew Primus, Cassisi said the club would concentrate on the positives to be found from the match.
From an individual standpoint, those positives were easy to find.
Robbie Gray booted a career-best six goals in a superb small forward's display, Travis Boak worked tirelessly in collecting seven clearances from his 23 disposals, and David Rodan delivered the ball superbly into forward 50.
Exciting young key forward John Butcher took his career goal tally to 11 from three games with a four-goal haul.
His three majors in the second quarter all came from strong contested marks, helping the Power turn a 21-point deficit at the mid-point of the term into a seven-point half-time lead.
In the end though, the young Power line-up just couldn't hang on.
"We put up such a great effort for most of the day, but it just came down to the clearances and the stoppage work, and they really got on top of us," Cassisi said.
"We can learn from it, but we'll take a lot of positives out of today."
Port will finish its season against Melbourne next weekend, in its first match at future home ground the Adelaide Oval.
A win is likely to see the bottom-placed team climb above Gold Coast and avoid the wooden spoon.
"We look forward to getting to Adelaide Oval," Cassisi said.
"It's a big occasion for the footy club and I think if we can produce what we did today, we'll give ourselves every chance to win next week."
