The survey's flash services sector PMI rose to 53.7, the highest reading in a year, from 52.6 in March.
Economists polled by Reuters had forecast the services PMI falling to 51.5.
Flash PMIIn the euro zone, the bloc's dominant services industry saw already-buoyant demand rise too, more than offsetting a deepening downturn in manufacturing.
However, the manufacturing PMI fell to 45.5 from 47.3, its lowest since the coronavirus pandemic was cementing its grip on the world three years ago.
"The PMI sheds a positive light on the economic performance in the euro zone, as a pickup in service sector activity is boosting growth," said Bert Colijn, senior euro zone economist at ING, noting manufacturing weakness remained a concern.