In the first-set tiebreaker, Nadal saved three set points, but lost the fourth on a Carreno forehand winner he could only watch go past.
Nadal took early control of the final two sets. He posted 30 winners and took advantage of five of nine break points in the two- hour match.
“He played well,” Nadal said. “I changed a little bit at the beginning of the second. I played with a little bit higher intensity and being a little bit more aggressive. So, very happy the way that I managed to change the dynamic of the match.”
Earlier, Illya Marchenko of Ukraine upset defending champion and fourth-seeded David Ferrer 6-7 (8), 6-3, 6-2 for his first career top-10 victory.
“He was better than me for all the match,” Ferrer said.
Before beating Ferrer, the 94th-ranked Marchenko had never even won a set off of a top-10 opponent in four previous attempts.
“I feel great beating a guy that high ranked,” said Marchenko, reporting he received congratulatory text messages from people he hasn’t talked to in years. “And I have really huge respect for David. It’s huge moment for me.”
Third-seeded Tomas Berdych of the Czech Republic defeated Sergiy Stakhovsky of Ukraine 7-5, 6-4. (AP)