Heather Knight has finally given long-suffering England fans the Ashes captain's ton they've craved.

The only problem for those watching through the night back in England: It was otherwise much the same story for their national team as it has been all summer.

Knight did what England men's captain Joe Root was unable to do on three trips to Australia, converting a half-century into three figures with her chanceless unbeaten knock of 127 in the women's Ashes Test in Canberra on Friday.

Unfortunately for Knight, she found herself with the same problem Root had so often this summer as she watched teammates throw away wickets at the other end.

Two of the top five fell playing away from their body, while Charlie Dean perished in the deep trying to take on Ashleigh Gardner with the score at 6-150 just the ball after she had been dropped.

Knight's knock therefore kept a desperate England in the Ashes, as only No.10 Sophie Ecclestone joined her in passing 15.

The pair's unbeaten 66-run ninth-wicket stand helped England avoid the follow-on, going to 8-235 at stumps on day two, still trailing by 102.

Untroubled on the Manuka Oval wicket, Knight ground her way to a 213-ball century, the second ton of her Test career.

It was the first time a male or female England captain had scored a century in Australia since Charlotte Edwards in 2010-11.

Knight drove superbly throughout, hitting 13 boundaries as well as a big six over mid-wicket off Ashleigh Gardner.

Her score is already the equal-biggest by a touring woman in a Test in Australia, joining Smriti Mandhana's score from earlier this summer.

England veteran Katherine Brunt rated it one of the finest innings she'd seen in her 17-year international career.

"I've been around a long time now and seen many great hundreds. And that just there is top three," Brunt said.

"Because not one (other) person scored a significant score.

"So she's taken the whole world on her shoulders and dug extremely deep to put a score on the board and achieve that milestone for her.

"It's top three in terms of importance too."

Brunt also had a big day as she completed the third five-wicket haul of her career, and her first in 12-and-a-half years.

Her ball to dismiss Melbourne Stars teammate Annabel Sutherland was arguably the best of the match as it beat her bat and took off stump, after she had also removed the likes of Alyssa Healy and Rachael Haynes on day one.