The latest quarterly statistics from the Welsh Assembly show that 56.2 per cent of services met the target in the quarter ending March 2007, in the same period last year it was 56.7 per cent.
Mr Murray said the government's figures did not reflect the month-by-month improvements the service had made across all 22 health boards in the past three months.
'The service is the best it's ever been. We've achieved our goal consistently since March and in April set a new record by reaching 66.3 per cent within the target', he said.
Mr Murray took over the service in August last year when it was underperforming and at the start of this year introduced a series of measures to cut call delays, including analysing emergency calls that could be handled by alternative services and introducing rapid response vehicles in areas with highest demand.