"No one expected it," said Pliskova, who had 15 aces, after the German hosts failed to win a set.
Goerges lasted only an hour with 23 unforced errors against the 10th-ranked Kvitova, who dropped just two points on her serve in the second set and converted four of five break points.
It was Kvitova's 29th singles win in the Fed Cup.
The German team will have to win both reverse singles matches and the doubles on Sunday to reach its first final since 2014.
"I think everything is possible in the Fed Cup," Goerges said. "Nothing's decided yet. We shouldn't lose hope.".
The 10-time champion Czechs have a 7-1 head-to-head record over their hosts. The Germans' only win came in 1987 when Steffi Graf was part of the team that beat Czechoslovakia 2-1 in the World Group semifinals in Vancouver.