OASIS Academy Shirley Park has been judged to be outstanding in a near flawless Ofsted report.
The glowing assessment shows the huge strides the school, given top marks in all categories, has made since being formed from merger of Ashburton infant, junior and community schools in 2009.
Principal Glen Denham, described by Ofsted as an "inspiration", said: "We are incredibly proud of being an outstanding academy that serves one of the most deprived areas of the country.
"The credit for this goes to the staff, our children and their families. We all share the belief that our children have the right to an outstanding education."
Three quarters of the academy's students are from ethnic minorities, well above average, and many join the school at a low level.
Inspectors who visited the Shirley Road school last month found that, regardless of their starting points, all of its 1,539 pupils make outstanding progress to "greatly exceed" the national average by the end of Year 11.
Teachers were described as "highly committed to ensuring that their students fulfil their potential".
"They have very high expectations of the students and successfully challenge, nurture and support them at every stage in their studies," the report, published on Wednesday, said.
Lead inspector Bill Stoneham said students take "immense pride" in the academy and their behaviour is outstanding.
"Students are offered many opportunities to excel," the report added.
"A wide variety of clubs, societies, educational visits and charitable efforts, both at home and abroad, help to make the provision for spiritual, moral, social and cultural development exceptionally strong."
The report quoted a Year 9 pupil who said teachers had "transformed my life", a comment echoed by many other students, it said.
The academy has an "unstinting commitment" to ensuring equality of opportunity and tackling possible discrimination, it added.
Mr Denham said: "It's true many of our students arrive with us at levels of achievement significantly below the national average.
"Many arrive from outside the UK midway through their primary or secondary education, with little or no English.
"Others have a history of disaffection in other schools that has led to exclusion.
"But, our job as teachers is to find the key to unlock the potential of every child.
"We accept no excuses and we have extremely high expectations about behaviour and attitudes towards others.
"No day is without its challenges, but the radical transformation in our academy shows what can be done when a community, a school and dedicated, talented staff work together. Quite simply, they transform lives."
The academy had been judged as satisfactory by Ofsted following its last inspection in February 2012. As a community school it had been viewed as one of the most "at risk" in the country.
Since then GCSE results have improved rapidly from well below average in 2011 to well above the national average in 2013.
If it is to improve, this week's report said, the school must ensure all work is accurately marked and assessed.
The sparkling review follows the academy came out as one of the best in the country when comparing the achievements of pupils from similar backgrounds.
Reverend Steve Chalke, the Croydon-born founder of Oasis Community Learning, said: "Growing up in South Norwood I knew the story of the predecessor schools only too well.
"When Oasis opened the academy we knew our job was to tell a new story, one of hope, perseverance and self-belief.
"I literally cried when I heard what this new story had been able to achieve."
