The academy trust that runs Highfield Leadership Academy in Highfield Road, South Shore, released a statement ahead of the release of a damning Ofsted report.
As inspectors accused senior teachers of having an "overgenerous view of the school's effectiveness", with their report saying they "underestimate many endemic weaknesses that are clearly apparent", Shirley Gornall, executive director of quality assurance at Star Academies, said she was proud of youngsters' achievements since the trust took over in 2016.
She said: "We do not believe the behaviour observed by Ofsted inspectors was typical of the hardworking and respectful pupils in our school.
"The inspection came at the end of a difficult term when we were not in a position to present the school in its best light.
"We are proud of the achievements of our young people and school over the past three years. We have secured much improved GCSE results, attendance, and behaviour.
"In addition, our pupils have engaged in hundreds of community projects, delivering thousands of hours of volunteering and raising thousands of pounds for charity.
"Despite these improvements and proud achievements, we recognise there is a long way to go and a lot of hard work ahead before we get to an acceptable standard of learning for all of our young people.
"We will continue to work hard to ensure the recommendations in the report are implemented.
"We are in no doubt that our children deserve better and will leave no stone unturned to deliver for them."
Ms Gornall joined Star from Ofsted, where she was an inspector in the north west, according to the trust's website.
Previous to that, she was a school improvement adviser for a local authority, and had originally trained as a secondary English teacher, going on to lead a "very successful" English department.