Virginie Razzano claimed her second successive WTA singles title on Saturday with victory over top seed Venus Williams at the Japan Open - but only afte saving three match points.

Fresh from her win at Guangzhou, fifth seed Razzano upset the top-seeded American, 4-6 7-6 (9-7) 6-4 in Saturday's final.

Razzano, who won the first title of her career in China last week, extended her winning streak to 10 matches en route to the championship at this Tier III hardcourt event.

"I've had injury problems over the last few years but I've been OK this year and I've been working very hard," Razzano said.

"I've been patient and have gotten stronger, and that's why I'm playing well this year. I'm very proud of my title last week and this week is also an incredible achievement for me."

Williams looked almost unbeatable coming into the match as she had steamrolled her way through the tournament.

The world number eight didn't lose a set in her first four matches at this event and had won 18 of her last 19 sets overall.

"I think I made the right decision playing here," Williams said. "It was a really great time. I love Tokyo. The fans are great and they were pulling for me to win today, which always feels good. I have no regrets - I had a great time."

After taking the first set, the Wimbledon champion looked well on her way to capturing her fourth title of the year.

But the owner of 36 WTA titles, who has an impressive 47-9 record this season, failed to win a gruelling tie-break in the second set, missing three match points, before falling in the deciding match.

"(Razzano) managed to play really well at all of the right moments, so congratulations to her," Williams said.

"I wasn't tired, in fact, I was feeling pretty fit. I know she feels very good about this win, it's a very good win. She's having a great year."

The 24-year-old Razzano reached a career-high world ranking of 33 after last week's title in Guangzhou and a trip into the top 30 is not out of the question after this effort.