The Essex school's 100 per cent clean sweep in maths, English and science gives it the highest raw score of the 495 mainstream schools taking part in the Government's pilot.
But the school does almost as well in the new value-added assessment, ranking fourth with a value-added score of 103.5. This suggests the school's success is down to excellent teaching rather than simply a high-performing intake of children.
Although Cold Norton primary is situated in a fairly affluent village near Chelmsford, deputy head Lisa Fergus says that it has a more mixed intake than might be assumed.
It started its own value-added assessments two years ago using a system called Target Tracker, recommended by Essex County Council.
This predicts one level of achievement that should be manageable for each child, and a second target, that is slightly higher. This latter, more challenging goal is what the school aims for.
Mrs Fergus says using extra money to teach pupils in small groups has helped the school hit these targets.
Last year an extra teacher was employed every morning for two months, enabling the mixed Year 56 class of 26 pupils to be split between two teachers and an assistant.
Mrs Fergus hopes that parents will come to appreciate and understand the new value-added tables.
"Parents' understanding of them at the moment is confused - I think they will just look at the percentages," she said. "But we will certainly highlight our value-added results to parents in our annual report. We will really go overboard on that."