ADELAIDE: World number two Aryna Sabalenka's Australian Open preparations were in tatters on Tuesday when she self-destructed for the second week in a row and was almost unable to serve at an Adelaide warm-up event.
A week after her delivery deserted her at the first of two Adelaide lead-in tournaments, Sabalenka suffered the same fate as she was stunned in three sets by world number 93 Rebecca Peterson 5-7, 6-1, 7-5.
Sabalenka dished up 21 double faults and was reduced to serving underarm in the second and third sets in a desperate effort to get the ball into play.
She took so much pace off her first serves that at one stage they were barely clearing the net.
The 23-year-old Belarusian became distressed in the third set and, after being asked by the umpire whether she was all right, broke down in tears during her next service game.
Her only consolation was that she was still hitting her groundstrokes with power and placement, but it was no surprise when she bowed out at the first hurdle.
"That was definitely the weirdest match I've ever played," Swedish qualifier Peterson said. "It was tough staying focused. I know she was struggling a lot.
"I just had to stay in my own world -- it was really difficult."
American teenage sensation Coco Gauff blasted her way to the second round with an impressive 6-1, 6-2 win over Czech player Katerina Siniakova.
The 17-year-old Gauff took just over an hour to dispose of Siniakova and set up a second round clash with fellow teenager Marta Kostyuk of Ukraine.
Fourth-seeded Slovenian Tamara Zidansek progressed when she saw off British qualifier Heather Watson 2-6, 6-2, 7-6 (7/4).
Seventh seed Jill Teichmann fell to US qualifier Lauren Davis 1-6, 7-6 (7/3), 6-4.
Australian wildcard Maddison Inglis beat Montenegro's Danka Kovinic 6-4, 1-6, 6-2, while other winners were American Madison Brengle, who downed Russia's Anastasia Potapova 7-5, 4-6, 6-1 and Czech player Tereza Martincova, a 6-4, 3-6, 6-3 winner over Ukraine's Dayana Yastremska.
In the men's draw, fifth-seeded South African Lloyd Harris was ousted by South Korean Kwon Soon-woo 5-7, 7-5, 6-4, while Australian wildcard Thanasi Kokkinakis continued his recent good form with a 6-4, 6-0 win over Frenchman Benoit Paire.