Nadal is playing in this tournament for the first time
World number one Rafael Nadal moved smoothly through to round two of the Japan Open in Tokyo with a 6-4 6-4 win over Santiago Giraldo of Colombia.
The 24-year-old top seed was beaten by Guillermo Garcia-Lopez in the semi-finals of the Thailand Open last week.
He saved two break points in the second set but won in an hour and 50 minutes.
Second seed Andy Roddick beat Japanese wild card entrant Tatsuma Ito 6-4 6-3 but Jo-Wilfried Tsonga, seeded three, lost 6-4 5-7 6-1 to Jarkko Nieminen,
Roddick, the 2003 US Open champion, was playing his first match since losing in the second round to Serbia's Janko Tipsarevic at Flushing Meadows in September.
The 28-year-old American took the first set when Ito double faulted on set point.
He had to recover from a break down in the second set but duly completed his victory in 82 minutes with an ace.
"Since New York, I've just been working on getting back my physical shape and I feel that I've been able to do that," said the former world number one, who has been beaten three times in the Wimbledon final by Roger Federer.
"He played very well in the first set. It was a little bit uncomfortable, because he hits every ball hard and flat and the court is very fast, so there wasn't a chance to get into my rhythm.
"In the second set, I don't think he played as well, but on this fast surface, it's certainly uncomfortable."
Meanwhile, Nadal, who missed 24 out of 26 break-point chances in his surprise defeat against compatriot Garcia-Lopez, missed his first five break point opportunities before forcing Giraldo to mishit a backhand, which put him a break up at 3-2.
After denying Giraldo his break in the fourth game of the next set, Nadal, winner of six titles this year, then produced a sizzling, trademark forehand winner from the baseline to break in the next game.
Giraldo had another chance in the eighth game but fired a backhand long and though he sent down two aces in the following game to hold serve, Nadal calmly served out to conclude the match.
He was not happy with his serve, however, and said: "That wasn't part of the strategy for sure. I started too many games love-30. My serve was the worst it's been for my last 11 or 12 matches.
"I arrived from Bangkok two days ago at seven in the morning so I'm a little more tired than usual. I have to play with more energy in my next match."
In other encounters, eighth seed Michael Llodra of France fell to Marco Chiudinelli of Switzerland 6-3 6-0, but his compatriot and fifth seed Gael Monfils safely went through, with a 7-6 (12-10) 6-4 victory over Go Soeda of Japan.