Australian top seed Ashleigh Barty has won her debut match at the Qatar Open and waltzed straight into the quarter-finals as a result.

The world No.1, appearing as the top seed at a WTA event for the 12th time, dispatched German qualifier Laura Siegemund 6-3 6-2 in the second round on Tuesday.

Barty was drawn to face Elena Rybakina in the round of 16 after the 14th seed battled past Alison Van Uytvanck 5-7 6-2 7-6 (10-8).

However, Rybakina was forced to withdraw from the tournament after her win due to what she said was "a small strain in my leg", gifting Barty a passage to the last eight.

Barty racked up 19 winners in her win over Siegemund, who owns three wins over top-five players and had come through qualifying before beating Yaroslava Shvedova in the opening round.

Barty's greater consistency and serving potency was too much for Siegemund in the one hour and 13 minute match.

"It took some time to adjust just to the conditions and having not played my opponent before," Barty told WTA.com.

"Happy overall to be able to switch on when I really needed to.

"Disappointing to have a few lapses in concentration but also a credit to my opponent, she came up with some really good stuff in runs to be able to break me a few times."

Australian Open finalist Garbine Muguruza powered past Australian Ajla Tomljanovic 6-1 6-2.

Tomljanovic was broken five times in eight service games as the Spanish 11th seed cruised to victory.

In other results, Sofia Kenin lost her opening match for the second week in a row as Dayana Yastremska defeated the American major winner 6-3 7-6 (7-4).

Kenin has yet to win a WTA Tour match since earning her first grand slam title at Melbourne Park last month.

"I just feel like I can't find my game, I'm not playing the way I want to be playing, so it's pretty frustrating right now," Kenin said.

Others to advance to the round of 16 on Tuesday included third-seeded Czech Karolina Pliskova, Swiss fourth seed Belinda Bencic and Petra Kvitova, the Czech eighth seed.