British number one Johanna Konta made her earliest exit from the Australian Open by losing to Tunisia's Ons Jabeur in the first round.
Konta, seeded 12th, was beaten 6-4 6-2 by the tricky world number 78 at Melbourne Park.
The 28-year-old was playing only her second match in almost five months because of a knee injury.
Konta struggled to settle as Jabeur knocked out Britain's highest-ranked player.
Five other Britons play later on Tuesday, which features a packed schedule with 96 first-round matches needing to be completed after the opening day was washed out by heavy rain.
British number three Kyle Edmund will shortly resume his match against Serbia's 24th seed Dusan Lajovic with a 5-2 lead.
Fellow Britons Katie Boulter, Heather Watson, Harriet Dart and Cameron Norrie should also play as planned with a much-improved weather forecast.
Rusty Konta unpicked by Jabeur
Konta, a 2016 semi-finalist at Melbourne Park, went into this year's opening Grand Slam having played only one match since September's US Open.
A tendonitis-like inflammation of the knee, which she suffered in the latter stages of last season, has had to be carefully managed.
Although she did not look troubled by the problem against Jabeur, Konta did show signs of rust and was unable to take her game to the levels that took her to the French Open semi-finals, along with the Wimbledon and US Open quarter-finals, last year.
Konta hit 19 unforced errors, while Jabeur also punished her with 19 winners.
The Briton's serve came under immediate pressure from Jabeur, who is able to unsettle opponents with her variety, and she had to save a break point in the opening game.
After steadying herself, an erratic game where she struggled on her first serve enabled Jabeur to strike and take the opening set.
Konta, backed by a healthy number of British fans, came out for the second set with renewed purpose, playing more aggressively to break in the opening game.
However, she was unable to back that up with a hold and from that point Jabeur took control to win in just one hour and two minutes.