Czech fourth seed Petra Kvitova crashed out of the Australian Open on Saturday, falling in straight sets to unseeded American teenager Madison Keys, who is coached by former great Lindsay Davenport.
Madison Keys of the US celebrates after her third round victory over Czech player Petra Kvitova on day six of the 2015 Australian Open in Melbourne on January 24, 2015
World number 35 Keys, 19, defeated the reigning Wimbledon champion 6-4, 7-5 in the third round, setting up an all-American last 16 clash with Madison Brengle.
"My hands are still shaking, right now I can't even process this, I'm just so excited," she said, paying tribute to the "amazing" Davenport, a three-time Grand Slam champion who won in Australia in 2000.
Like Davenport, Keys is a big-serving baseliner with powerful groundstrokes, which she used to full effect against Kvitova, who has admitted to struggling with nerves throughout the tournament.
The Czech, who was a semi-finalist at Melbourne Park in 2012 but lost in the first round last year, allowed Keys to dictate terms in a poor performance which included six double faults and 32 unforced errors.
Keys, who has never before advanced beyond the third round of a major, looked comfortable on the big stage and went up a break in the fifth game.
Kvitova broke back but Keys responded with another break and held on to serve out the set with an ace after 36 minutes.
The second set followed a similar pattern, with Keys on the attack amid an early exchange of breaks.
Kvitova tried to move Keys from her baseline comfort zone but the American rose to the challenge and the Czech double faulted to concede a second break.
The 24-year-old again broke back but Keys kept pressing and brought up two break points at 5-5, hitting the first wide but converting the second for a chance to serve out the set when Kvitova's return failed to find the corner.
It proved decisive as Keys coolly held the Czech to love, serving out the match for her biggest ever win.