World number one Iga Swiatek says she has to be "ready for everyone" after overcoming 2020 champion Sofia Kenin in the Australian Open first round.

Poland's Swiatek, who has never reached the final, won 7-6 (7-2) 6-2.

The top seed faces another tough test in the next round, where 2022 runner-up Danielle Collins awaits after she beat 2016 champion Angelique Kerber.

"You never know who it is going to be and you have to be ready no matter what," Swiatek said about the draw.

"Tennis is a sport where the draw means you can play a former champion, a former world number one or someone with lots of experience.

"I try not to focus on who is going to be on the other side of the net, I want to play my game and I know if I am going to win this tournament I have to beat most of the girls."

Swiatek, who has won three French Open titles and the 2022 US Open, is playing well and beat 41st-ranked Kenin to earn a 17th successive win.

"It is not easy to play in the first Grand Slam of the season and it wasn't easy at the beginning to find my rhythm," Swiatek added.

"I was a little bit off and Sofia did everything to keep it that way. She's won here so knows what it takes. Huge respect to her."

American Collins beat Swiatek in the semi-finals on her way to the 2022 final in Melbourne and overcame Kerber's experience with a 6-2 3-6 6-1 victory.

Kerber, a three-time Grand Slam champion, returned to action just two weeks ago as part of the German team at the United Cup, having spent 17 months off the tour to have a baby.

Elsewhere in Tuesday's first-round matches, American fifth seed Jessica Pegula cruised through with a 6-2 6-4 victory over Canadian qualifier Rebecca Marino to set up a round two match with France's Clara Burel.

Kazakhstan's third seed Elena Rybakina - who was beaten by Aryna Sabalenka in last year's Australian Open final - defeated former world number one Karolina Pliskova and will face Russian Anna Blinkova next.

Belarusian 18th seed Victoria Azarenka beat Italian Camila Giorgi 6-1 4-6 6-3 and will meet Danish world number 100 Clara Tauson in the second round, while Russian 14th seed Daria Kasatkina also successfully navigated her way through a tricky opening test, winning 6-2 3-6 6-2 against powerful American Peyton Stearns.

Former US Open champion Sloane Stephens won 6-3 6-1 against Australian wildcard Olivia Gadecki.