Victoria Azarenka of Belarus comes to the net against Daniela Hantuchova of Slovakia during their women's quarterfinal match at the US Open tennis championships in New York, Sept 4, 2013. [Photo/Agencies]

NEW YORK - Victoria Azarenka struck a blow for the younger generation by beating Daniela Hantuchova of Slovakia 6-2 6-3 to join a trio of 31-year-olds in the semifinals of the US Open on Wednesday.

The 24-year-old Belarusian, the second seed and runner-up last year, will play unseeded Italian Flavia Pennetta, while defending champion Serena Williams meets Li Na of China in Friday's semifinals.

Pennetta reached her first Grand Slam semifinal on Wednesday by beating longtime friend and Fed Cup team mate Roberta Vinci, the 10th-seeded 30-year-old, 6-4 6-1.

Azarenka is well aware she is battling the 'old guard' in last four.

"I'm a baby, what can I say?" she added. "It's amazing to see such great players in the semifinals."

The victory moved Australian Open champion Azarenka one step closer to a possible Arthur Ashe Stadium rematch against Williams for the title.

"It's amazing to see athletes doing so well, their careers longer so fans and themselves can enjoy their careers much better," she said. "Everybody looks much fitter, really taking care of their body and taking the sport to the next level."