British qualifier Harriet Dart was unable to maintain a strong start as she lost in the Australian Open first round to seventh seed Iga Swiatek.
Dart, 25, broke for a 2-1 lead in the first set as she settled quickly and hurt Swiatek with some classy winners.
But Poland's Swiatek, 20, found her rhythm, winning five games in a row to turn the match in her favour.
The 2020 French Open champion continued her high level in a one-sided second set to wrap up a 6-3 6-0 victory.
After coming through Melbourne qualifying for the third time in her career, 123rd-ranked Dart was handed another plum first-round draw which again put her on Rod Laver Arena.