Dramatic improvements at Thomas Becket Catholic School, in Northampton, led to a leap in the pass rate for A-level results.
This summer the proportion of students gaining A to E grades rose from 75 per cent to 91 per cent, with the A to C grades rising from 34.8 per cent to 41 per cent.
Sixth-former Harry Fraser, 18, was over the moon after being awarded As in English language, psychology and biology. He will study sciences at Sussex University.
Headteacher Paul Gardiner said: "We are very pleased with the performance of all of our students this year.
"Their successes are a reflection of the hard work by the subject teachers and by the students themselves."