Japan's number one tennis player Kei Nishikori has accepted responsibility for his side's failure to beat Croatia in the first round of the Davis Cup World Group.
At number 20 in the world, Nishikori was the highest-seeded player in either side, but was demolished by the 43rd-ranked Croatian Ivo Karlovic in a straight sets loss.
The 208cm-tall Karlovic also dismissed Nishikoria's compatriot Go Soeda without facing a break point, while also teaming up with Ivan Dodig for a doubles victory in the middle of the three-day series.
In an interview following the decisive match in which Soeda sacrificed his team's chances of a come back, Nishikori acknowledged: "I was the one who had to put up two wins for my country.
"Given the fact I didn't get two wins here, I definitely have more room to improve."
The 22-year-old was full of confidence coming into the competition having reached the quarter-finals of the Australian Open in Melbourne, with recent scalps including top seed Novak Djokovic and Jo-Wilfried Tsonga.
After seeing his country knocked out of the Davis Cup World Group, however, he vowed to come back better than ever.
"I'll try to become a player who can always win both of my two matches in a Davis Cup series," he said.
Following the result, Japan captain Eiji Takeuchi declared his intention to resign following eight years in the role.
"Karlovic singlehandedly knocked us out," he said, before praising the big-hitter's serve-and-volley game and consistent groundstrokes.
"My players had little chance against him."
Captain of the Croatian side, Zeljko Krajan, also lavished praise on Karlovic, declaring that with the way he is playing it will be difficult for any of the Davis Cup teams to beat them.
This was the first time since 1995 that Japan have made it to the World Group stage of the Davis Cup.