In an exciting back-and-forth rubber lasting three hours 45 minutes, Siniakova held off the 19-year-old Fed Cup debutante to give the Czechs a 3-0 win in the final against a United States team who were the defending champions but were missing their top players.
· The semi-finals: Czech Republic beat Germany 4-1 to reach the final, the U.S. beat France, 3-2.
The Czech team, facing a usa squad without their top players and fielding three debutantes, will take a 2-0 lead into Sunday as they seek a sixth Fed Cup title since 2011.
She came close but was denied two matchpoints by doubles expert Siniakova, who stepped into singles play with world number eight Karolina Pliskova out with injury and twice Wimbledon champion Petra Kvitova sick.
"In the second set I got a lot of break opportunities but she just played too good so credit to her".
The clash will begin with Kenin taking on Barbora Strycova before Riske faces Katerina Siniakova.
Another mainstay on the Czech Fed Cup team in recent years, Lucie Safarova, announced on Saturday she will retire from tennis after the Australian Open because of health problems.
Siniakova cruised in the first set but fell behind in the second before pulling level.
The reverse singles, for which Kvitova could be drafted in if well enough, take place on Sunday, ahead of the final doubles rubber between world number one pair Siniakova and Barbora Krejcikova and Melichar and Collins.
The 32-year-old Czech player was more dominant at the net and her stronger serve helped see off the young American.
The USA can take comfort in their record against their opponents, having not lost to the Czechs in eight meetings dating back to 1985, while they are on a seven-match winning streak after beating Belarus in the final previous year.
"For me it was a lot of emotions", Strycova said on court after the win.
"I fought every ball and I'm so happy that I could win today in front of such a crowd".
"It is amusing because it is her first (Fed Cup tie) and it is my last one", Strycova said.