The five-time Grand Slam champion overcame a slow start to win 6-3, 6-2.

The Polish star, who was given a one-month doping ban late last year, is playing for the first time since losing in the Melbourne semi-finals to eventual champion Madison Keys.

World number two Swiatek will next face either Kazakh Yulia Putintseva or Czech youngster Linda Noskova in the last 16.

The 23-year-old has not dropped a set at the Qatar Open since her second-round win over Viktorija Golubic in 2022.

Swiatek's victory in the tournament last year was her first of four WTA 1000 titles in 2024, taking her total tally to 10, the equal most among current players with Victoria Azarenka.

Former world number three Sakkari took three successive games to move a break up in the first set, but could not get on the board again until the fifth game of the second.

Greek Sakkari saved a match point en route to a hold of serve to make it 5-2, but Swiatek secured victory on her own serve as her opponent fired a return wide.

Earlier, the 20-year-old Noskova notched an impressive 6-2, 6-4 win over 15th seed Donna Vekic in the first round, while Putintseva edged out Moyuka Uchijima in three sets.

Russian 10th seed Daria Kasatkina demolished Polina Kudermetova 6-0, 6-0 in just 42 minutes to set up a last-32 tie with Armenia's Elina Avanesyan.

Jelena Ostapenko also cruised into round two, beating Japanese qualifier Aoi Ito 6-2, 6-1.