Kvitova opened with a 6-2, 6-1 victory over Bethanie Mattek-Sands and Berdych beat Mardy Fish 6-3, 6-3. Berdych saved four break points while serving for the match before converting his first match point to ensure the Czechs won their second straight match at the eight-country tournament.

The teams will play a mixed doubles match later Wednesday which will help determine final placings in Group A, where the Czechs are strong favorites to qualify for Saturday's final.

The US fell to 0-2 after losing to Denmark in their opening match.

The Czechs and Denmark play each other Friday, featuring a women's singles encounter between No. 1 Caroline Wozniacki and the second-ranked Kvitova, while the US plays Bulgaria.

Earlier Wednesday, Bulgaria's Tsvetana Pironkova and Grigor Dimitrov came back from a set down to win the deciding mixed doubles and complete a 2-1 victory over Wozniacki and Frederik Nielsen.

The Bulgarians won the mixed doubles 3-6, 6-4, 10-1 after a champions tiebreaker, leaving both teams with 1-1 records in Group A.

Wozniacki had given Denmark the lead when she beat Pironkova 7-5, 4-6, 6-2 but Dimitrov leveled for Bulgaria, beating Nielsen 7-6 (5), 6-2.

Wozniacki beat American Bethanie Mattek-Sands in straight sets in her first singles match Monday just hours after arriving from Thailand.

On Wednesday, she and Pironkova both struggled with their serves and Wozniacki was given a code violation for receiving coaching from her father during the seventh game of the third set.

"It was a tough match. I like to give the spectators a little bit of value for their money," Wozniacki said. "I'm not a real morning person so 9:30 is pretty early for me." Nielsen put up stiff resistance in the first set before Dimitrov dominated in the second.

"It was definitely a tough match today. The guy was attacking at every opportunity," Dimitrov said. "I got a bit lucky on some shots. He played some great tennis." In Group B on Thursday, winless Australia and China play in the morning before France and Spain, both 2-0, play at night. The winner of France-Spain will advance to the final from that group.