World number two Serena Williams believes almost losing to Barbora Strycova will leave her in good stead at the Australian Open.

Williams was unconvincing as she reached the quarter-finals with a 7-5 6-4 win over the Czech at Melbourne Park on Monday.

The 22-time grand-slam champion served at just 45 per cent, was broken on four occasions, while she tallied 46 unforced errors compared to Strycova's 14 on Rod Laver Arena.

Williams, however, feels she will be better for the test heading into the last eight.

"I feel like it was really good for me to win on probably not my best day, which is always good," the American veteran told reporters. 

"Sometimes you rely on one shot and if it goes off, and then what happens now?

"It was really good for me to almost lose that so I know my other game is going pretty good, too."

Of Strycova, who impressed, Williams continued: "She's hard to read, she's scrappy, gets a lot of balls back. She definitely plays a different game than the other three players I played before.

"It was definitely -- it gave me a different look. But it was interesting."

Next up for Williams is Johanna Konta in the quarters at the Australian Open after the ninth seed trumped Ekaterina Makarova in straight sets.

Konta will provide another stern test in Melbourne but Williams claims she has nothing to lose as she looks to win a 23rd major.

"She's been playing really well. She has a very attacking game. I know her game pretty well. I look forward to it," Williams said.

"I have absolutely nothing to lose in this tournament. Everything here is a bonus for me. Obviously I'm here to win. Hopefully I can play better, I can only go better."

The women's singles draw has opened up for Williams following Angelique Kerber's shock elimination in the fourth round but the 35-year-old sympathises with the dumped world number one and defending champion.

"It's been a couple interesting weeks for Angie," Williams added. "She's been dealing with a lot. I think she was able to handle it the best she could.

"I think Coco [Vandeweghe] played really well. I think she really just came up with a wonderful game plan, and it was an easy match so it wasn't too surprising."