MELBOURNE (AFP) - Venus Williams' 69th Grand Slam came to a premature halt in the first round on Tuesday when she was shocked by rising British star Johanna Konta, who was making her Australian Open debut.

The oldest player in the women's draw, whose maiden Australian Open was in 1998, had high hopes coming into the season's first major tournament after a rich vein of form late last year.

It propelled her back into the world top 10 but Williams, 35, was no match for Konta, who raced to a 6-4, 6-2 victory in 79 minutes on Rod Laver Arena for one of the biggest wins of her career.

Seven-time Grand Slam champion Williams, who won the inaugural WTA Elite Trophy in 2015 as well as tournaments in Auckland and Wuhan, never got her game going.

A quarter-finalist last year, she was broken twice in the opening set in blazing heat as the 24-year-old's Konta's younger legs carried her further than the American veteran.

It didn't get any better in the second set with a despondent Williams, her left thigh heavily strapped, unable to handle the Konta serve or find the shots to hurt an opponent oozing confidence.

Sydney-born Konta, who only became a British citizen in 2012, raced to a 5-0 lead before Williams broke for a consolation game and then held, before her opponent wrapped it up.

Ranked 47th, 98 spots higher than this time last year, Konta has grown by leaps and bounds in the past 12 months.

She upset current world No. 3 Garbine Muguruza at the US Open last year en route to her first round of 16 at a Grand Slam.