CORI “COCO” Gauff sent five-time Wimbledon winner crashing out of the Australian Open on Monday, repeating last year’s straight set success at the All England Club.

The tenacious US teenager, who registered the day’s fastest serve in the ladies draw at 118.7mph, booked her second round berth with a hard-fought 7-6(5) 6-3 success on her main draw debut Down Under.

Veteran Williams, who had not played since October, was rusty throughout and visibly wilted after losing the opening set on a tie-break.

The Margaret Court Arena, filled to the maximum capacity of 7,500 spectators, witnessed the 15-year-old schoolgirl brilliantly outmanoeuvre her idol who is 24 years her senior. And the contest was the youngest player against the oldest in the ladies draw.

Last year’s Wimbledon meeting saw the legendary Williams suffer a shock 6-4 6-4 reversal, this time more was expected from the seven-time Grand Slam singles champion who had time to prepare for the tricky encounter.

Despite her decades of experience at the highest level it was a nervous start by Williams, who served double faults in both her opening service games, which instilled confidence into her opponent.

Gauff broke in the opening game to 15 then followed it without dropping a point on her serve. After starving off a break point, the teenager thundered down an ace to carve a 3-1 lead.

Williams managed to level matters at 5-5, having saved two set points and been gifted the game by a double fault, with each player holding then their serve to force the lottery of a tie-break.

Gauff initially outplayed her compatriot to storm into a 5-2 lead, but overzealous shots crept in before she calmed her nerves to seal the set on the 12th point.

More variety was required by the youngster in the second set, with some clever drop shots introduced to steal away to a 5-3 lead. And her fearless approach paid dividends.

Gauff made no mistake to finish off Williams with a game to love to book her place in the second round and prove that she is a rising star.