Serena Williams' 17th appearance at the Australian Open remains on track - the 22-time Grand Slam singles champion beat fellow American Nicole Gibbs 6-1, 6-3 at Rod Laver Arena.
The 23-year-old Gibbs, making her 12th appearance overall at any major, had two game points at 1-1 in the second set, but allowed Williams to come back and break her serve.
Williams was broken at 5-2 while serving for the match, but did the same to Gibbs in the next game to complete the win in 63 minutes.
The six-time Australian Open champion advanced to the fourth round for the sixth year in a row since not playing here in 2011 due to a foot injury.
Aiming for a record 23rd Grand Slam singles title, Williams will next play Barbora Strycova, who beat Caroline Garcia in straight sets.