After winning the toss and electing to bat first, openers Elyse Villani (32) and debutant Amy Jones (57) put on nearly 80 runs for the first wicket to get the Scorchers off to a fast start.
Number three Nicole Bolton (40) then combined brilliantly with Jones to help the visitors to 2-109 early in the 12th over, before Jones was bowled by Dane van Niekerk.
Three quick wickets to the home side stopped the Scorchers momentum in it's tracks, Perth eventually posting 167 from their 20 overs.
Perth's bowlers toiled hard, but a century to Sixers captain Ellyse Perry was the difference between the two sides, after the home side reached the total with eight balls to spare.
Jones, who also took a sharp catch behind the stumps to go with her 29 ball half century, said not capitalising on their good start proved costly.
"We didn't really cash in at the end after the start we had, if we had a set batter going into the last few overs we might've scored a few more runs," Jones said.
"I know we could have been a bit better in the field so that's an area we'll need to improve on if we're to jump back on the winners list.
"Our match against Brisbane tomorrow is a chance for us to put a few things right that didn't go our way tonight.
"They've got some great players in their squad so it will be an exciting challenge and hopefully we can get the win."
Perth play the Brisbane Heat at North Sydney Oval tomorrow in their third match of WBBL|04, with the first ball bowled at 11:50am AWST live on 7mate.