Spectators at a rugby tournament in Rolleston watched the magnitude 5.5 earthquake move like a wave across the sports fields on Monday morning.
Rolleston Rugby Club president David Egan, says six games were underway at the Rolleston Reserve for a seven a-side competition involving players aged from four to 16 years.
He says there was a jolt before the tremor rolled across the fields towards the clubhouse, which jumped and shook.
Mr Egan says vehicles, including a coffee van, were temporarily lifted off the ground, but the teams barely hesitated before continuing their matches.
He says the quake did not cause any obvious damage to the grounds or clubhouse.
Rolleston is 2km from the epicentre of Monday's quake.