MELBOURNE, Jan 17 (Reuters) - Former world number one Caroline Wozniacki said she felt old at the age of 22 while Kimiko Date-Krumm, 20 years her senior, took a look around the locker room and realised she was old enough to be the mother of many of her rivals at the Australian Open.
However, age, cunning and guile appears to be winning out over youthful vigour at the year's first grand slam as all but three of the 11 teenagers to make the women's second round were bundled out of the tournament.
Despite whisperings of a generational shift at Melbourne Park, only the American duo of Madison Keys and Sloane Stephens and Britain's Laura Robson remain in the main draw after Thursday's matches.
The cull was victory of sorts for the 'middle agers' like Wozniacki and 'senior citizens' like 42-year-old Date-Krumm.
"I still want to try to feel young out here," a laughing Wozniacki told reporters after she beat London-based Croatian teenager Donna Vekic 6-1 6-4. "But, you know, it's the way of life, I guess. 22, it's old in the tennis world."
The former world number one, who made her professional debut as a 15-year-old wildcard at Cincinnati in 2005, said she could hardly believe that Vekic was 16.
"I mean, she's six years younger than me. That's crazy. That definitely makes me feel old," Wozniacki said smiling.
Vekic, coached by Briton David Felgate, is on the verge of breaking into the world's top 100, but her inexperience showed in the end against Wozniacki.
"I thought actually she was going to go for more, but I could tell that she can keep the ball in play and go for it when she needs to," the Dane added.
"You can see she can develop physically and still be stronger at things.
"She's going to improve a lot over the next few years (and) I definitely believe that we're going to see a lot of her in the future."
While Wozniacki was prepared to tip Vekic for a bright future, 17-year-old Keys is already being touted as the new face of American women's tennis, earning plaudits from commentators, past players and her fellow professionals.
Keys, the daughter of two lawyers with no history in the sport, came into the tournament as a wildcard and destroyed Austrian 30th-seed Tamira Paszek 6-1 6-2 in the second round.
"Really fun watching Keys play," former world number one Lindsay Davenport wrote on her Twitter account after the victory over Paszek.
"Regardless on how this tourney plays out, incredible potential. Best hope I've seen for U.S. since Williams'."
Keys will meet fifth seed Angelique Kerber in the third round on Friday, and third seed Serena Williams, thinks her compatriot has the game to win a grand slam -- before she is 20.
"There are some players, like Madison Keys ...she's very strong and she's only 17," Williams told reporters after her second round win over Spanish teenager Garbine Muguruza.
"She has several years while she's still a teenager to win a grand slam."
Martina Hingis still holds the record as the youngest female player to win a grand slam title, when she clinched the Australian Open in 1997 aged 16 years, three months and 26 days.
World number two Maria Sharapova won Wimbledon as a 17-year-old in 2004, while Williams won her first grand slam at the U.S. Open, just days before her 18th birthday in 1999.
It is now doubtful, however, whether a player could seal a grand slam title before they turn 18.
The WTA has capped the number of tournaments a player can play before the age of 18, hence restricting their ranking points and often forcing them to go through qualifying.
The game has also evolved to be dominated by more powerful players, who tend to be older as they have matured physically.
"When I was 17, I think I was playing pretty good tennis, as well as Hingis and the other teenagers that won," Williams said. "I think if the person is strong enough physically and mentally, I think it's completely possible, but think that will be a little more tough, to be 16, 15."
Australian-born Briton Robson, 18, made her breakthrough last year when beating Li Na and Kim Clijsters at the U.S. Open and claimed another big scalp past midnight when she knocked out former Wimbledon champion Petra Kvitova.
The left-hander will face Stephens in Saturday's third round in what could be a glimpse of future grand slam battles. (Editing by Martyn Herman)