Over half of all grades earned by GCSE students at Northampton's Caroline Chisholm School this morning came in between A* and B.
The mixed all-through school in Wootton Fields says they have done "as well as last year" despite new, harder exams.
Three-out-of-four students passed their English and maths exams with a level four or higher, while two pupils, Eddie Sambridge, only dropped 16 marks out of 240 across his Maths exams.
Headteacher David James said: "We're very happy with our results, especially with the new exams. We had no idea our marks this year would go up or down.
"We don't have the past papers or the guidance or the experience when working with the unknown. You think you're teaching at a certain level but you don't know until the results arrive."
One student, Dominique Woodford, earned a 9 in her Maths, the highest grade possible under a new system brought in this year.
Dominique said: "I was very nervous but my maths teacher ran up and asked me to open them in front of her. I'm really pleased with my results."
Bridget Ballantyne, head of maths, said: "I think the foundation paper was a lot harder. It was harder to teach too. We had no idea what a 9 looked like.
"Only about two per cent of the nation will get a 9 in maths, and Caroline Chisholm has hit three per cent. We're very pleased."