The Sixers first rode on a brilliant bowling display by spinner Nathan McCullum (3/24) and pacer Josh Hazlewood (3/22) to dismiss Highveld Lions for a modest 121 in their stipulated 20 overs after winning the toss and electing to field.
The Australian side then returned to overhaul the target with 7.3 overs to spare, thanks to some powerful hitting by opener Michael Lumb and Brad Haddin, who notched up an unbeaten 124 run partnership.
Chasing 122 to win, Lumb annihilated the Lions with eight fours and five sixes in his 42-ball 82-run unbeaten innings, while his opening partner Haddin blasted four boundaries and a six in his 33-ball unfinished 38 here.
The opening duo were in marauding form as they toyed with the Lions bowlers, taking them to the cleaners every now and then. They were particularly harsh on Chris Morris and Aaron Phangiso as the bowlers bleded 54 in four over combined.
Lumb finally finished off the chase in style when he blasted Pretorius for a six over deep wicket in the first ball, pulled the next over fine leg and then sent the third delivery across the boundary line as well to trigger celebration for the Sixers.
Earlier, McCullum and Hazlewood claimed three wickets each to help Sydney Sixers dismiss Highveld Lions for a modest 121 in the finals.
Sydney Sixers broke the back bone of the Lions as they reduced them to 9-4 in just 3.3 overs after winning the toss and electing to field.
Jean Symes top-scored with a 46-ball 51 to help Lions put up a total or else things could have been more embarrasing for the home team at the New Wanderers Stadiums here. MORE