Iga Swiatek admits the strict doping protocols can be stressful for players but feels like she has "been through the worst" after surviving her positive test over contaminated melatonin.
Swiatek said she made far too many mistakes against Keys on Rod Laver Arena and hoped to draw lessons from it.
The Polish second seed was phenomenal on a gusty day at Rod Laver Arena, powering past the eighth seeded-American 6-1, 6-2 in 1hrs 29mins.
Romania's Simona Halep on Friday rounded on the International Tennis Integrity Agency (ITIA) for discrepencies in the treatment of world number two Iga Swiatek after testing positive for a banned substance.
"The player was provisionally suspended from Sept. 22 until Oct. 4, missing three tournaments, which counts towards the sanction, leaving eight days remaining," the ITIA said in a statement.
The 26-year-old jumped above Poland's French Open champion Iga Swiatek thanks to year-end adjustments in the standings.
Top seed Swiatek, who won the title two years ago, showcased her all-court game in a straightforward 6-4, 6-1 win over Russian Liudmila Samsonova to open the evening session at Arthur Ashe Stadium and warned she was only going to improve.
Four-time French Open champion Swiatek was equally dominant as Sinner as the top-seeded Pole eased into the fourth round with a 6-4, 6-2 victory over Russia's Anastasia Pavlyuchenkova.
World number one Iga Swiatek of Poland withdrew from next week's WTA event in Toronto on Friday, citing fatigue from her run to a bronze medal at the Paris Olympics.
World number one Iga Swiatek on Wednesday called for prize money equality between WTA and ATP events.
World number one Iga Swiatek defeated Australian Open champion Aryna Sabalenka in straight sets to win her second consecutive Stuttgart title on Sunday.
It is Swiatek's first title of a year, and follows her shock fourth-round exit in the Australian Open at the hands of Wimbledon champion Elena Rybakina
World number one Iga Swiatek was knocked out of the Australian Open Sunday as Wimbledon champion Elena Rybakina blew the women's draw wide open by beating the red-hot favourite in straight sets.
World number one Iga Swiatek fired an Australian Open warning to her rivals with a crushing 6-0, 6-1 win over Spanish qualifier Cristina Bucsa on Friday.
World number one Iga Swiatek is the favourite to win an Australian Open women's draw shorn of some of its biggest recent stars.
World number one Iga Swiatek survived a tough examination against Jule Niemeier on Monday to reach the second round of the Australian Open.
Iga Swiatek was left in tears after Jessica Pegula stunned the world number one on Friday to give the United States a 1-0 lead over Poland in the semi-finals of the inaugural United Cup.
Rafael Nadal lost his opening match of the season Saturday in the countdown to the defence of his Australian Open title, but women's world number one Iga Swiatek cruised to victory at the United Cup.
World number one Iga Swiatek was able to have her cake and eat it at the U.S. Open after the Pole capped her campaign at a star-studded Flushing Meadows by collecting her third Grand Slam title.
