The Scorchers victory means that Auckland Aces with six points were ousted as Delhi with 10 points and Nashua Titans with eight points were through.
A victory for Auckland against Perth today could have opened up the group, but the Australian side's bowlers stuck to their task. Chasing a modest target of 141, Auckland failed to capitalise on the 49-run second-wicket stand between opener Martin Guptill and Azhar Mahmood as they ended on 124 for eight in their stipulated 20 overs.
Perth clawed their way back into the match with four quick strikes in the middle overs.
Left-arm spinners Michael Beer and Brad Hogg and pacer Joe Mennie shared bulk of the spoils between them. Beer was the stand-out performer as the Victorian finished with impressive figures of three for 13. For Auckland, Guptill top-scored with 32-ball 36 while Mahmood, who looked well set en route his 24, was caught by Gibbs.
Perth Scorchers 140/7 in 20 overs (P Collingwood 38, M North 37, M Bates 4/34); Auckland Aces 124/8 in 20 overs (M Guptill 36, A Mahmood 23, M Beer 3/13)Semifinal line-up:
Oct 25: Delhi Daredevils vs Lions at Durban (9 pm)Oct 26: Sydney Sixers vs Titans at Centurion (9 pm)