Sydney Sixers 126 for 1 (Perry 82*) beat Sydney Thunder 123 (Knight 38, Litchfield 34, Gardner 4-26) by nine-wickets
Sydney Thunder were left having to undertake a hasty cross-country journey in their bid to reach the WBBL final after falling to defeat against local rivals Sixers at the SCG.
Victory would have secured Thunder a home Challenger final on Wednesday, but instead they will have to take the long route to the final - in every sense - after Ellyse Perry's unbeaten 82 secured a comfortable nine-wicket win.
Thunder will now face Brisbane Heat in the Eliminator on Tuesday at the WACA before the winner backs up against Perth Scorchers a day later in a bid to play Adelaide Strikers in next Saturday's final.
Such is the condensed nature of schedule, the Thunder players boarded a coach to the airport immediately after the Sixers match concluded to catch a five-hour flight to Perth and ensure they had a day to prepare in the city on Monday.
Thunder's regular season has stuttered to a conclusion after they were well placed to push for top spot a couple of weeks ago. Instead, five defeats in their last six games has seen them cling onto fourth place meaning they (and Heat) will have to win three matches to take the title.
"It's frustrating, there was that real carrot of staying in Sydney and having a home semi-final," Thunder captain Heather Knight said. "But, I've just said to the girls now, if you'd said at the start of the year that we were going to make finals after winning just [five] games in two years we'd have taken it.
"We are obviously going to have to do things the hard way now with a flight over there and win three games to try and win it. We've got to park what happened in the back of the group stages and move on."
Against Sixers, in front of a crowd of 7118 to complete the three days of matches at major stadiums, a batting collapse proved costly as Thunder lost their last eight wickets for 39 including the last five in the space of 11 balls.
Although the tempo hadn't been high, Chamari Athapaththu and Phoebe Litchfield had laid a foundation only for the innings to crumble after they fell. Litchfield was going along nicely when she rifled a drive to mid-off which was well held by Suzie Bates.
From there, wickets tumbled against Sixers' spin duo of Ashleigh Gardner and Linsey Smith while three run outs added to their problems. Knight attempted to hold the innings together with a run-a-ball 38.
Thunder thought they had broken through early when Sam Bates had Suzie Bates lbw, but DRS showed there had been a thin bottom edge on the sweep.
From there an opening stand of 59, dominated by Perry, set the base for the chase before Bates fell to a brilliant leg-side stumping by Tahlia Wilson. But Perry eased to a 44-ball fifty and finished the game in a rush of boundaries leaving Thunder to collect their already-packed bags and head straight to the airport.