Headteacher George Varnava broke short his holiday in Cyprus to be at the "failing" London school he has run since December when GCSE results arrived.
More than half of the 60 staff at Ashburton High in Croydon also turned out.
"I was very moved when I saw how many came to see how their pupils had done," said Mr Varnava, the trouble-shooter brought in to turn round the 11-16 mixed comprehensive.
Ashburton is one of the 11 secondary schools "named and shamed" by the Government at the end of the last academic year for making insufficient progress while under special measures: a list of so-called failures.
The commitment was matched at schools around the country where the summer was spent devising plans to save them from closure.
At Ashburton the number of pupils gaining five or more top grade GCSEs rose from 18 per cent last year to 20 per cent. At the top end, seven pupils gained A* passes and only 12 pupils left with no qualifications at all.
Low achieving pupils have been given individual attention, and the installation of computers in the support unit has had an enormous impact on raising standards, according to Mr Varnava.
An Easter revision programme was instigated for the GCSEs and about 70 of the 200 prospective candidates pupils attended.
At Earl Marshal, a mixed 11-17 comprehensive in Sheffield, the proportion of pupils gaining five or more A-Cs increased from 8 per cent last year to 11.5 per cent.
Headteacher Alun Pelleschi, brought in by the local authority a year ago, has replaced many staff. A SMART team - special measures action recovery team - has also been allocated to the school.
An Easter and Spring school was introduced, a twice-weekly homework club was set up, and senior staff have been involved in mentoring.
Most of the pupils have English as a second language and a large number came from the Yemen as refugees during the civil war.
Mr Pelleschi said: "We have targeted youngsters who we felt were capable of attaining C grades but were just falling below the line. Our results not only show an improvement in that band but also a major increase in the number of grades which have risen from E or F last year up to D."
Dulwich High School for Boys in south-east London reported a huge jump in the proportion of boys achieving five A-C grades in this year's result - rising from 9 per cent to 21.3 per cent.
Headteacher Lloyd Van Marshall said, however, that there had been no significant changes in teaching practice. For the past few years the school has targeted boys with low literacy standards and offered additional time and support to individuals.
"Fundamentally students in our Year 11 group this year were more committed to achieving than those in last year's GCSE's group," he said, adding: "The percentage could easily fall again next year.
"We do not have many high-fliers but we will continue to try to enrich the lives of the targeted groups by encouraging them with homework clubs, visits to further education institutions and our own mentoring system."
At Blakelaw School, a Newcastle comprehensive, top grade results fell by 0.9 per cent to 9.2 per cent.
Headteacher Russ Wallace has spent the whole summer devising a business and curriculum plan to turn round the school (see left).
"Staff, parents and the local authoritiy have been working together. We want a Fresh Start. We are desperate for it," he said.