TOKYO -- Japan won its Davis Cup World Group tie on Sunday, clinching a quarterfinal berth when Frank Dancevic of Canada was forced to retire in the second set of his reverse singles match with Kei Nishikori.
With Nishikori leading 6-2, 1-0, Dancevic withdrew with a stomach injury giving Japan an insurmountable 3-1 lead.
"I pulled a stomach muscle," Dancevic said. "I hurt it in a serve in the second set and there was no way I could continue against a player like Kei."
It was the latest in a series of injuries for the Canadians. Milos Raonic pulled out with a left-foot injury on Thursday while Vasek Pospisil, who was originally slated to play doubles on Saturday, was unable to recover in time from an injury.
Nishikori, who is No. 18 in the world rankings, won both his singles matches and also played in Japan's doubles win on Saturday.
"The pressure is always on me to win both singles matches," Nishikori said. "This time I was able to help win three matches."
Japan improved to 6-0 against Canada in Davis Cup play. The two countries last met in 1938. Japan advances to the quarterfinal round for the first time and will face either the Czech Republic or the Netherlands.
Go Soeda beat Peter Polansky 6-1, 6-4 in the dead rubber to widen the lead to 4-1.
OSTRAVA, Czech Republic -- Defending champion Czech Republic reached the quarterfinals of the Davis Cup on Sunday after Tomas Berdych won the first reverse singles to clinch the first-round series.
Berdych, an Australian Open semifinalist, dispatched Thiemo de Bakker 6-1, 6-4, 6-3 on an indoor hard court at CEZ Arena to give the Czechs an unbeatable 3-1 lead. In the final meaningless match, Igor Sijsling defeated Lukas Rosol 6-3, 6-3 to reduce the Czech overall victory to 3-2 in the best-of-five series.
Berdych was never threatened and converted his first match point with a forehand winner. He hit 35 winners to De Bakker's 18.
Seeking their third straight Davis Cup title, the Czechs won their 10th consecutive Davis Cup series. They will travel for the April 4-6 quarterfinal to Japan, which beat Canada 4-1.
"I want to enjoy the victory now and we'll see what happens next," Berdych said.
The seventh-ranked Berdych improved his record to 3-1 against the 139th-ranked De Bakker, who surprisingly beat the Czech at an ATP tournament in Bastad, Sweden, last year.
"I may not have the best record against him," Berdych said. "Today I was ready."
Berdych also swept aside Sijsling 6-3, 6-3, 6-0 in the opening singles on Friday and produced another dominant performance on Sunday.
He didn't waste time and broke De Bakker's first two service games in the opening set for a commanding 5-0 lead.
Berdych secured a break in the seventh game of the second set and served it out with an ace.
De Bakker hit the net in the opening game of the third set to lose his serve and Berdych broke him again with a forehand winner to race to a 4-1 lead. Berdych lost his only serve to allow de Bakker to reduce his lead to 5-3 before breaking him again in the following final game of the match.
De Bakker replaced the originally nominated Robin Haase, who was tired after spending almost eight hours in the previous two days on the court in the eastern Czech city of Ostrava.
Haase gave the Netherlands a 1-0 lead with a 3-6, 6-4, 6-7 (4), 6-2, 6-1 win over Radek Stepanek in the opening singles match on Friday and teamed up with Jean-Julien Rojer for a 7-5, 1-6, 7-6 (2), 7-6 (4) loss to Berdych and Stepanek.