Japan took a stranglehold of their Davis Cup world group playoff with Brazil on Friday as Yuichi Sugita and Go Soeda won the opening day's singles, albeit in contrasting fashion.

Sugita beat Guilherme Clezar 6-2, 7-5, 7-6 with quiet efficiency in Osaka before Soeda almost snatched defeat from the jaws of victory in a nail-biting 3-6, 6-4, 6-3, 6-7, 6-4 win over Thiago Monteiro.

Soeda had played his way back into the second rubber with the use of clever angles and lobs before a sudden meltdown in the fourth set opened the door for his opponent.

He corrected the wobble by breaking in the sixth game of the decider and a backhand return on his first match point forced Monteiro into a wild forehand that ballooned long.

Soeda crumpled into a heap as the ball flew past the baseline after more than three and a half hours on court.

"I felt a lot of nerves at the start and lost my way a bit but I managed to hang in," said the 33-year-old.

"He put me under real pressure and I had to dig in at times. I've tried a lot of things to improve the mental side of my game, so I was happy to get through it."

Looking to bounce back from a stinging defeat by France in February and return to the competition's top tier, Japan are without former US Open finalist Kei Nishikori, who has ruled himself out for the rest of the season with a wrist injury.

Japan have preserved their world group status with playoff wins in the past two years and will hope to complete the treble by winning Saturday's doubles.

"Today was a big step towards achieving that but we have to keep our feet on the ground," said Japan captain Satoshi Iwabuchi. "We still have to finish the job."

New Zealander Ben McLachlan, who has switched allegiance to play for Japan, is expected to make his Davis Cup bow in the doubles.