Australia 331 for 6 dec and 64 for 1 lead England 314 (Knight 157, Marsh 55, Osborne 4-67) by 81 runs
Heather Knight made her first Test century as England continued their dogged rearguard action well into the third day at Wormsley. Knight's 157 from 338 balls was the seventh-highest Test score by an England woman and she was joined by the equally obdurate Laura Marsh in a stand of 156 - England's best for the seventh wicket and one run shy of the Test record - that went a long way to staving off the threat of defeat to Australia.
With six points on offer in these multi-format Ashes, the incentive to win was clear and evinced by Jodie Fields' decision to declare with her team six down on the second day. But with the prospect of defeat coming at such a price - a draw will give each side two points - England have knuckled down in an attempt to make sure they don't lose. Australia had extended their lead to 81 by reaching 64 for 1 by the close, making a draw the most likely result.
Resuming on a perilous 172 for 6, still 149 runs behind, Knight and Marsh forged on in the same manner in which they had gone about their business on the on previous evening. The pair soaked up 73 overs of pressure before Knight was run out after being sent back looking for a single.
Knight was dropped on 105, wicketkeeper Fields missing a chance down the leg side, but by then she had long-since surpassed her previous best innings, in her only other Test, of 19. She hit 20 fours in all and was particularly strong off her pads in making the third-highest individual total for England against Australia.
Marsh, 13 from 114 balls at the start of the day, had progressed to 35 when she lost her partner and Katherine Brunt, who hit her first ball for four, went soon after. But Danielle Hazell stuck around for another 20 overs as Marsh went to her first Test half-century, eventually facing 304 balls for her 55. By the time Australia claimed the final wicket, Erin Osborne finishing with 4 for 67, the deficit was just 17.
"I'm really pleased, I think when I went in we were pretty up against it," Marsh said. "I was just really pleased to be able to hang in there with Heather and support her.
"It was the job the team needed and I tried to stick in there and be disciplined with my decision-making. It was really helpful to have Heather at the other end for the vast amount of the time I was there because she just played brilliantly and we kept each other going.
"I tried to be positive in defence and approach it that way and pick up runs when they became available."
With a slim lead and a potentially tricky couple of hours to negotiate amid rain showers, Australia's openers began at a similarly watchful pace, reaching 40 before Jenny Gunn removed Rachael Haynes. First-innings centurion Sarah Elliott accompanied Meg Lanning safely to the close but it will take something special from the usually attacking Fields to force a result.