More than a quarter of pupils at Archbishop Michael Ramsey technology college in Southwark, south London, achieved at least five good GCSE passes this year, double the number two years ago.
Mr Blunkett wants every secondary to get at least 20 per cent of its pupils achieving five good passes, rising to 25 per cent by 2006.
Making such a leap in such challenging circumstances made the achievement all the sweeter, said head Wendy Parmley.
Nearly three-quarters of pupils are eligible for free school meals, almost half the pupils had changed school and 80 per cent are already three years behind in their reading by the time they arrived.
The vast majority of the school's pupils are boys, and most of these are from nationally under-achieving ethnic-minority groups. The fact that they are bucking the trend particularly pleases Mrs Parmley. Nearly half the students are of African heritage, a further 30 per cent are from African-Caribbean families.
She credits the bedding-in of existing schemes for this year's sccess, as no new initiatives were needed to achieve this year's jump from 16 per cent to 26.5 per cent getting at least five good passes.
She said: "We laid the roots in 1998 and 1999 and this year our labours are beginning to bear fruit.
"All our ideas had been tried out with preceding cohorts: all our pupils had a mentor and the "critical kids", those on the CD borderline, had almost daily monitoring in those crucial six months leading up to the exams."
In the run-up to GCSEs pupils followed a six-week motivation programme of revision and exam technique and the parents of the weakest candidates were either invited into school or visited at home. Extra Saturday classes were provided throughout the school year and pupils were given access to all school facilities during the Easter holidays.
Mrs Parmley, head for eight years, is delighted to have overseen the school's success since it went into special measures in February 1998.
She said: "Not many heads survive their schools going into special measures - most either move or are moved on. I feel really blessed to have had such support from my governing body who have kept challenging us to improve."