PRAGUE -- Russia won both singles matches to defeat Switzerland 2-0 in the final of the Billie Jean King Cup on Saturday to claim the trophy for the fifth time.
"It's too many emotions now," Samsonova said. "It's unbelievable. I'm unbelievably happy."
The competition was formerly known as the Fed Cup.
Samsonova broke the Swiss star in the opening game of the final set and held on to serve it out when Bencic's backhand sailed long.
Bencic stayed calm in the opening set against the big-hitting Russian, who produced 16 unforced errors compared to her three, and got the key break in the eighth game.
Samsonova improved in the second set, hitting 14 winners before serving it out.
She replaced originally selected Russian No. 1 Anastasia Pavlyuchenkova at the last minute. Pavlyuchenkova withdrew because of a left leg injury.
Russia has all of its players in the top 50.
Samsonova's victory came after she beat Bencic twice at WTA tournaments in Berlin (final) and Luxembourg (quarterfinals) this year.
In a dominant display, Kasatkina blasted a forehand winner to earn a break point in the seventh game of the second set that she converted for a 4-3 lead. She was not able to hold her serve in the following game but got another break for 5-4 before serving the match out on her first match point.
The Russian stormed the opening set, breaking Teichmann three times and dropping her serve once.
"I think the beginning was very important, we were both nervous but I managed little bit better the nerves," Kasatkina said.
It was the second victory for the Russian in the tournament after beating Canada's Carol Zhao in the group stage to improve her record in the competition to 5-1 while Teichmann recorded her first loss after three wins.
"An amazing feeling," Kasatkina said. "I won the first match (in the group stage), now I play in the final and I'm happy I've brought this very important point to my team."
Russia reached its first final since 2015 in the competition they won in 2004, 2005, 2007 and 2008.
The Swiss reached their first final since finishing runner-up in 1998, their only final appearance
The 12 teams in the tournament were divided into four groups of three in a new competition format. Only the group winners advanced to the semifinals.
Russia dominated Group A in the tournament after victories over defending champion France and Canada before eliminating the United States in the semifinal.
The U.S. is the most successful nation in the competition with 18 trophies.
Switzerland advanced to the semis from Group D, considered the toughest in the tournament, defeating both the Czech Republic and Germany on the way.
In the semis, the Swiss swept Australia 2-0, winning both singles matches.
Prague's tournament failed to attract bigger names including Garbiñe Muguruza, Karolina Pliskova and Aryna Sabalenka, who opted to get ready for the WTA Finals that open Wednesday in Guadalajara, Mexico.