On a dramatic Sunday at Trent Bridge, Australia fell from 1-149 to all out for 257 in their second innings, after star spinner Sophie Ecclestone fuelled two separate collapses of 6-49 and 3-0.
England then got away to a flyer in the chase, and looked as if they could pull it off in a canter when they scored 0-55 from their first 10 overs.
Then Gardner arrived.
After the finger-spinning allrounder took 4-99 in the first innings, she removed the in-form Tammy Beaumont with her first ball in the second innings.
Fresh off scores of 201 in a warm-up game and 208 in the first innings at Trent Bridge, Beaumont squeezed Gardner to first slip on 22 where Beth Mooney took the catch.
Gardner then got rid of veteran Nat Sciver-Brunt in her next over for a duck on a top-edged sweep, before a sharp-turning delivery trapped Heather Knight lbw for 1.
Ecclestone is widely regarded as the world’s best spinner but Gardner must be in the conversation.
“I think Ash isn’t too far behind her,” Australia opener Beth Mooney said.
“She has been outstanding for us in the past couple of years.
“There was a time two or three years ago where Meg tended to not throw the ball to Ash in T20 cricket.
“To her credit she changed what she did and changed her variations and things like that.”
England opener Emma Lamb also fell in the collapse, lbw to Tahlia McGrath when ball-tracking showed it would have clipped leg stump.
Kim Garth then struck in the shadows of stumps to have Sophia Dunkley caught behind for 16, leaving Danni Wyatt (20no) and nightwatcher Kate Cross to fight to the close with 152 more needed.
England will need to not only pull off the biggest successful chase in a women’s Test to win, but also eclipse the record for the highest fourth-innings score in any result.
“They had the ball on a string in the last 60 minutes,” Mooney said.
“It’s pretty tough conditions once the ball gets a bit soft.
“The game is teetering … but we feel like we are probably the happier team walking off.”
Australia, for their part, would still feel life could be more comfortable.
They were cruising late in the morning session, before England debutante Lauren Filer claimed Ellyse Perry’s wicket for the second time in the match on 25 and also bowled McGrath for one with her pace.
Ecclestone then took command, claiming her second five-wicket haul of the Test and making for match figures of 10-192.
She bowled Jess Jonassen sweeping on 14, had Mooney chop on to a ball that spun back to her sharply on 73 and got first-innings Annabel Sutherland caught pulling on 15.
Alyssa Healy survived a dropped chance first ball that would have marked her fourth straight Test duck, before she posted a counter-attacking 50 to give Australia something to bowl at.
But just when she and Alana King looked set to take Australia to a lead of 300 with a 59-run eighth-wicket stand, Australia lost 3-0 with Ecclestone taking the last two wickets to finish with 5-63 for the innings.
“We will always believe. We will go into tomorrow ready to win this Test match,” Ecclestone said.