Maria Sharapova of Russia reached the semi-finals of the US Open on Wednesday with a hard-fought 7-6 (7/4), 7-6 (7/0) win over Tatiana Golovin of France.
The third seed will play top seed Amelie Mauresmo of France for a place in the final.
Tournament top draw Sharapova had coasted through the first four rounds losing just 15 games in the process but in former Florida sparring partner Golovin she hit her first real obstacle.
The Russian-born 18-year-old refused to be awed by the big-hitting, big-screaming diva of women's tennis giving as good as she got in a no-holds barred clash.
She also matched the 19-year-old 2004 Wimbledon champion in the fashion stakes with both clad in striking all-black outfits.
But she failed to convert two set points on the Sharapova serve in the 12th game and paid a heavy penalty in the ensuing tie-break which she lost 7/4.
She again stayed with Sharapova until the sixth game of the second set when the Russian opened her shoulders to move 4-2 ahead.
But in what was an increasingly nervy match, Sharapova conceded her own service with a sloppy game only to rebound immediately to get to 5-3 ahead.
Golovin refused to buckle and once again she got back on level terms.
But in the tie-break, she opened with three unforced errors and allowed Sharapova to run away with it 7-0.
"She's one tough cookie and we have always have tough matches," Sharapova said of her opponent with whom she used to train as a youngster at the Nick Bollettieri Tennis Academy in Florida.
"I've known her since we were little girls and we grew up together at the same academy."
Turning to Mauresmo against whom she has lost three times in three matches, the last being in the semi-finals at this year's Wimbledon, Sharapova said she would be the underdog.
"She's the one to beat right now. I've nothing to lose as she is playing the best tennis of her career."