Afghani import Rashid Khan underlined his importance to Adelaide Strikers in their 25-run win over Sydney Thunder at Spotless Stadium.
Khan took two wickets for the fifth straight BBL game, helping the South Australian side move into top spot.
The Thunder's own finals prospects have cooled with the visitors exposing their lack of batting depth and power hitting.
Khan hit 16 off six balls late in Adelaide's innings while South African Colin Ingram (48 off 31) made the biggest contribution to boosting the Strikers to 158-7, with 44 coming off the final three overs.
The could only muster 133-9 in reply, slipping to a fourth loss in six matches.
The Strikers are one of four teams with eight points so far but have edged ahead thanks to their net run rate, which is far superior to that of rivals Melbourne Renegades, Brisbane Heat and Perth Scorchers.
Adelaide's attack showed discipline in restricting the home side when they replied. Though veteran Ben Rohrer (29 off 13) clobbered 23 off the 18th over bowled by Ben Laughlin, the previous 10 overs had only yielded two boundaries.
Khan (2-21) has emerged as one of the excitement packages of the tournament and the 19-year-old legspinner continued his form.
He bowled in-form English opener Jos Buttler (21 off 21) and helped slow the Thunder's chase.
The home side's other key top order batsmen Kurtis Patterson (29 off 36) and Shane Watson (14 off 16) couldn't make the most of their starts.
Ingram belted four sixes and two fours and gave the Strikers' innings some much-needed momentum after they struggled to get going in the first 10 overs.
Adelaide are 3.75 to win the BBL title. The Strikers are 1213.00 to finish in the top four.
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