The table-topping Strikers can now finish no lower than second in the regular standings guaranteeing them a last-four clash at the Adelaide Oval later this month.
Craig Simmons (46 off 34 balls) and skipper Johan Botha (41 off 19) powered Strikers to 182-6 from their 20 overs in Sydney on Wednesday. Botha (2-27) and express paceman Shaun Tait (2-29) then bowled tightly and claimed two scalps apiece as the Sixers were dismissed for 159.
Sixers remain third in the Big Bash standings but may now have to beat city rivals Thunder at home on January 22 to rubberstamp a second successive semi-final appearance.
Strikers elected to bat after winning the toss in Sydney and raced to 46-0 midway through the fourth over, but Tim Ludeman (31 from 15) then cut Bollinger to wicketkeeper Ryan Carters having thrashed two fours and a six from the first three balls of the left-armer???s second over.
Jono Dean (13 from 12) joined Craig Simmons ??? who cracked the fastest Big Bash ton in history last season, off just 39 deliveries ??? at the crease and the pair put on 41 for the second wicket before they nicked off to Carters.
Strikers??? charge seemed to be stumbling when Travis Head (nine) was bowled by spinner Nathan Lyon with the first ball of the 15th over with the score on 115, but Botha then took charge, combining with Ryan ten Doeschate (26 from 20) to add 41 in just 20 balls.
Ten Doeschate was run out by Sean Abbott but Botha, who plundered three boundaries and two maximums during his thrilling knock, carried on hitting to help his side post a highly-competitive total.
Sixers openers Michael Lumb (17 from 16) and Nic Maddinson (18 from 14) picked up a collective five boundaries but both were back in the hutch before 50 was on the board after top-edging to short mid-off and short cover respectively.
Riki Wessels (15 off 20) and Sixers skipper Moises Henriques (10 off 12) came and went, before Carters (one), Abbott (two), Steve O???Keefe (five) and Brett Lee (seven) departed cheaply as Tait and Botha came to the fore.
Jordan Silk (67 off 34) blasted his maiden Big Bash fifty in an innings that included seven fours and three sixes, but he and then last man Bollinger (0) were run out by Ben Laughlin as the Strikers wrapped up victory.
Strikers??? success is in stark contrast to their first three seasons in the Big Bash, when they finished sixth, fifth and seventh and failed to progress into the knockout stages.