Air ambulance halts Lancashire's game at Old Trafford
It is believed that the spectator left the ground in one of three ambulances that also attended the scene.
Lancashire Cricket Club tweeted: "Play halted due to a medical emergency, with one of the spectators taken ill.
"The air ambulance has landed on the outfield. Let’s hope they (sic) going to be okay."
Play resumed at 11.45pm.
The two sides took lunch with Lancashire 6-2 in their second innings, a lead of five runs.