More than 2,000 Welsh pupils received improved GCSE grades this week after Wales' education minister Leighton Andrews ordered a regrade.
The WJEC exam board confirmed that following the regrading of its English language GCSE paper, 1,202 students improved from a D to a C, and 598 from a C to a B. Overall, 2,386 students received higher grades.
The Welsh government, which regulates exams in Wales, last week directed the WJEC to regrade its GCSE English language results after a review found significant problems with the grading methodology.
Mr Andrews said it was a "swift resolution of an injustice" served to Welsh candidates. "The decision to direct the WJEC to regrade was about fairness and ensuring that Welsh students got the grades they deserved for the work they put into their examination," he said.
"This announcement was the only acceptable outcome for learners affected by a questionable grading methodology. Candidates can now rest assured that the process used to determine their final grades was fair and just."
The news was widely welcomed by teaching unions. Philip Dixon, director of ATL Cymru, said: "We are delighted for these youngsters. They are now receiving the grades they would have received in any normal year. The minister is to be commended for such bold and decisive action. The few embittered voices who will try to deny these youngsters their success will clearly be seen for the politically motivated killjoys they are."
Rebecca Williams, policy officer at Welsh teaching union UCAC, said the problem had been rectified for the majority of pupils in Wales. "Their peers in England have no choice other than to await the November resits, and won't receive a final grade until the end of the year," she said.
"It's regrettable that we've found ourselves in this position in the first place. It just goes to show how easy it is for the qualifications system to become a political football when you've got two such different education ministers in Westminster and in Cardiff Bay."
Meanwhile, Mr Andrews has called plans to replace GCSEs in England a "backwards step" and said that Wales will not rush in to any reform. The Welsh government has commissioned an independent review of 14-19 qualifications and Mr Andrews said he will wait for its report, due at the end of November, before considering any changes.
The minister called education secretary Michael Gove's plans for an English Baccalaureate Certificate a "20th century approach." He said GCSEs were a "strong brand" with a lot of support in Wales and suggested they might be kept.
Conservative MP Alun Cairns, a former shadow education minister in the Assembly, claimed Welsh pupils will become "marginalised" and left with "out-of-date" qualifications if the reforms are not adopted.