The UK looked to set to escape a triple-dip recession as the economy's dominant services firms enjoyed their strongest growth spurt since the Olympics.
The Chartered Institute of Purchasing & Supply's (Cips) latest activity index – where a score over 50 signals growth –improved to 52.4 in March.
This was the best since August when the games gave a much-needed fillip to the economy.
Chris Williamson, chief economist at survey compiler Markit, said: "The Government and Bank of England will breathe sighs of relief in seeing signs of an ... upturn."
Markit's surveys – closely watched by the Bank of England – are consistent with 0.1% growth in the first three months of 2013, avoiding a technical triple-dip recession after a 0.3% decline in the final quarter of last year.
Official data also revealed an encouraging start to the year for the services sector with a 0.3% rise in output during January.
Cips chief executive David Noble said: "It seems that the service sector has finally found the ingredients, which – if mixed correctly – may well result in the right recipe for sustained growth in 2013."