The Pirates released the following statement:
"The female fan who was struck by a foul ball during last night's game was sent via ambulance to the hospital for the appropriate examinations. Thankfully, the fan was released from the hospital following those examinations.
"We are extremely grateful for this positive outcome. The organization is in the process of reaching out to her to show our support. Due to privacy laws, we will not reveal the name of the fan, nor additional details at this time.
"We wish to thank the PNC Park personnel and fellow fans who were on the scene at the time, as well as the Pittsburgh EMS for their quick response."
The game was delayed for 23 minutes while the fan received medical attention.
The fan was behind the protective netting behind home plate while Chicago Cubs shortstop Starlin Castro was batting. The ball, which did not appear to go through the netting, hit the woman with her back to the field of play.
Video of the incident, which some readers may find disturbing, can be seen here.
The spectator was eventually carted off on a stretcher.
The Cubs and Pirates each offered their condolences on Twitter.