Shanghai: Spain's David Ferrer saved three match points against injured Juan Carlos Ferrero to progress to the quarter-finals of the Shanghai Masters Thursday as impressive Andy Roddick also won.

Third seed Ferrer won the all-Spanish tie 1-6, 7-5, 6-2 after a major fright in the 10th game of the second set, where he was forced to dig deep to hold serve and prevent Ferrero from sealing the win in a match lasting two hours.

The win for Ferrer means he becomes the fifth player to qualify for the season-ending ATP World Tour Finals, featuring the world's top eight singles players over the year.

"I served very well in important moments," said the Spaniard, referring to how he saved the match points.

"I won this game, and after this game I made the break very fast. Maybe Juan Carlos, he was a little bit injured. Maybe in the third set it was more easy."

Speaking about qualifying for the season-ending showpiece, Ferrer said: "I think this season I have played really good tennis. I am very consistent. Maybe it is my best year of my career. I think so."

Injury-cursed Ferrero had strapping applied to his right ankle midway through the second set after a nasty tumble and although he recovered to force the match points, his challenge faded in the third set.

Nagging knee and wrist injuries have blighted the season for the 31-year-old former world number one, forcing him to miss three Grand Slams.

Earlier, 10th seed Roddick became the first player to reach the last eight after an impressive 6-3, 6-4 win over Nicolas Almagro, seeded seven, of Spain.

Playing under the closed roof at the Qi Zhong stadium, 10th seed Roddick secured a single break in each set, wrapping up victory with his 11th ace in a controlled display that saw him make just 14 unforced errors.

Roddick said his serve had worked well after he made an adjustment in the warm-up.

"As far as the way I've been hitting the ball and playing, it's been OK but the serve's been up and down. My percentages weren't where I wanted them to be," he said.

"I cleaned that up a little bit today. I think that makes everything look a little bit better. Then you go 2-2 on breakpoints, it makes it look pretty straightforward," he added.

Ukrainian 12th seed Alexandr Dolgopolov also reached the quarter-finals, beating Australian teenager Bernard Tomic 5-7, 6-1, 6-0.

Top seed Rafael Nadal will later face Florian Mayer of Germany and Britain's Andy Murray, the number two seed and defending champion, plays Stanislas Wawrinka.