Set a target of 185 to win, Australia were all out for 123 with Kate Cross and Anya Shrubsole each taking three wickets for England at the WACA.
England captain Charlotte Edwards had earlier passed the half-century mark to score 56 before becoming one of five victims for Australian bowler Ellyse Perry, while Jenny Gunn made 44.
Following the victory in Perth Edwards told BBC Radio 5 Live Sports Extra: "The last four days have been a rollercoaster, but I'm really proud of the girls.
"This is not the Ashes won, we've got to win more games now.
"We had some great performances... I'm so proud of them. We have to keep working hard and hopefully will take the Ashes home."
Three one-day international meetings and three Twenty20 games remain, with two points available for a win for each game.
Holders England need only win two of the six games to retain the trophy while Australia are tasked with winning five games from six.
The next appointment is an ODI at the MCG in Melbourne on Sunday and Australia captain Jodie Fields is looking for an improved display from her team.
"It was a great Test match to be a part of, but unfortunately we didn't come out on top," she said.
"We've got a great team and I didn't think we played to 100 per cent of our ability but hopefully we can bounce back."
All-rounder Perry, who dismissed Edwards, Lydia Greenway, Arran Brindle, Natalie Sciver and Cross, added: " I think everyone's really disappointed to lose such a tough Test match like that.
"The match turned and twisted, and those six points will go a long way in the Ashes but now we've got the limited-overs games.
"I think we've learned a lot from this game, but it would have been lovely to have won."
- Sports & Recreation
- Anya Shrubsole
- Ellyse Perry