The home side slipped to 12 for 2 after England’s captain had got their first innings close
Lunch Australia 337 for 9 dec and 12 for 2 lead England 297 (Knight 168*) by 52 runs
The ninth-wicket stand with Sophie Ecclestone was extended to 100, an England record, then No. 11 Kate Cross chipped in with a useful hand until Ellyse Perry’s third wicket ended the innings.
Brunt then made immediate inroads as the weather closed in, finding Alyssa Healy’s outside edge as the wicketkeeper bagged a pair and having Rachael Haynes taken at short leg with the penultimate delivery before rain arrived on the stroke of lunch.
It took Brunt’s match haul to seven wickets and carried her to 50 overall in Test cricket.
Knight, who resumed on 127, went past her previous best of 157 made in 2013 and become just the second batter to make two 150+ scores in Ashes Test after Karen Rolton. She had come out with positive intent from the start, unfurling a glorious cover drive, a hook against Perry and a slog-sweep off Jess Jonassen which took her to 150 off 274 balls.
It was a frustrating morning for Australia who had hoped to secure a far more substantial lead. When they finally bowled England out it felt a long time since there was talk of the follow-on.
Ecclestone was given two lives, both by Meg Lanning at slip, the first coming in the opening over of the day and another when she had 33 but that was a tough one diving to the right. She was eventually trapped lbw by Tahlia McGrath who became the seventh bowler to take a wicket.
Andrew McGlashan is a deputy editor at ESPNcricinfo