Updated

World number 12 Kei Nishikori banished his U.S Open demons to propel Japan back into the Davis Cup world group with a 3-2 comeback victory over Colombia on Sunday.

Nishikori rediscovered his mojo after a shock first-round exit in the United States earlier this year, showing the kind of form which swept him to the Japan Open title a year ago as he overpowered Santiago Giraldo 6-1 6-2 6-4 to level the tie for the home team.

Teammate Go Soeda held his nerve to beat Alejandro Falla 4-6 6-4 6-3 6-3, triggering wild celebrations in Tokyo.

Ripping winners from all over the court, Nishikori ran Giraldo ragged as he tore through the first two sets in just 56 minutes.

A blistering forehand down the line gave Nishikori the crucial break for 4-3 in the third and while Giraldo showed late resistance in saving four match points.

But it proved too little too late when moments later a fizzing backhand landed on his toes and the Colombian wafted a forehand wide to set the stage for Soeda.

"I got my rhythm back," said Nishikori, who won his third ATP Tour title in Memphis earlier this year. "In Davis Cup you have to sort of force yourself to be up for it and it's really helped me get re-motivated."

Soeda, ranked 123rd in the world, produced an even more impressive performance.

Having dropped the first set, Soeda caught fire at the end of the third and, after completing victory with a fierce forehand down the line, was mobbed by his team-mates to the deafening roars of a packed crowd of almost 7,000.

"I've never played in an atmosphere like that with so many people," said Soeda.

"I watched a yakuza (gangster) movie last night to fire myself up," he added with a sheepish grin. "To give me the stubbornness not to lose and help me become more of a nasty character."

Japan had returned to the top level for the first time in 27 years, only to be eliminated by Israel last year.

"These players deserve to be on the world stage," said Japan captain Minoru Ueda. "I had faith Soeda could pull this off."