Meridian High, in New Addington, has seen improved results in English and maths, despite the harder exams.
60% of students passed English and 43% passed maths, which the school said is an improvement on last year's results.
Head teacher Martin Giles said: “The improved results in English and maths give us confidence going forward that our students can do well under the new system, which focuses much more on exams and much less on coursework.
“English in particular was a very challenging exam so we are pleased that so many students were able to do so well.”
Head Boy Peter Okufuwa achieved a grade 9 in English language, putting him in the top 2% of students nationally – and As and A*s in every other subject – 10 GCSEs altogether.
Tegan Finch, pictured below, was one of Meridian’s top performers, with two A*s, four As and three Bs. A tearful Tegan said: “I was expecting to do worse than this but I did put in a lot of work. I’m very happy; I will probably start crying again later!”
Tegan plans to go to sixth form college in Coulsdon to study for A levels in maths, biology and chemistry, and hopes to make her career in some branch of human or veterinary medicine.