Pakistan was hosting a major ICC event for the first time in 29 years.
International teams refused to travel to the South Asian nation for years after gunmen attacked a bus carrying touring Sri Lankan cricketers in 2009.
What did PCB say in its statement?
In a statement issued on the spectator heading to the ground during the 50-over Champions Trophy match, PCB said: "The PCB has taken serious note of the security breach that occurred yesterday when a spectator entered the field of play. Ensuring the safety of players and officials remains our top priority."
"As a responsible organisation, we have engaged with local security agencies, who have committed to increasing security personnel around the field of play at all venues and strengthening access control measures," the statement said.
The man was seen carrying a poster of Tehreek-i-Labbaik Pakistan (TLP) chief Hafiz Saad Hussain Rizvi.
PCB said the intruder was arrested and produced before the court.
"He has been permanently banned from entering all cricket venues in Pakistan," the cricket board said.
"To prevent such incidents in the future, the PCB is working closely with security agencies and venue authorities to review and reinforce security protocols," the board said.
Rachin Ravindra scores century
Rachin Ravindra played a fighting 112 runs knock to help New Zealand beat Bangladesh in the Group A stage match to reach the semi-finals of the eight-nation tournament.
Kiwis victory also knocked out Bangladesh and hosts Pakistan from the tournament.