Sydney Thunder 125 (Knight 45, Day 4-35, McKenna 3-18, Sutherland 3-22) beat Melbourne Stars 121 for 9 (Darlington 5-10) by four runs

Hannah Darlington bagged her first five-wicket haul to crash Meg Lanning's retirement party and help the Sydney Thunder go top of the WBBL ladder with a four-run win over the Melbourne Stars.

Darlington claimed 5 for 10 at North Sydney Oval on Friday, as Thunder defended 125. The figures are the best of any bowler this season, and only second to Megan Schutt's 6 for 10 for the greatest by a quick in WBBL history.

Darlington's wickets included Stars captain Lanning, who was caught behind for 19 the day after announcing her shock retirement from international cricket.

Lanning had looked set to guide Stars to a much-needed victory, showing off her trademark cut shots and guiding the ball outside off stump with ease.

But when she edged a cut shot off Darlington through to wicketkeeper Tahlia Wilson, Stars' chase was suddenly in serious trouble.

Some late hitting from No. 11 Milly Illingworth got the equation down to nine off the last over, before Thunder spinner Chamari Athapaththu held her nerve to finish the game with a dot ball when five runs were required.

Lanning has set no end-date on her franchise T20 career, but Stars now need to see the very best of her over the final five games of this season. Sitting seventh on the ladder, they will likely need to win all of those matches to make the finals.

Darlington was the catalyst for the Thunder's win. She got England star Alice Capsey caught behind for 27, before dismissing Annabel Sutherland in the same fashion.

The 21-year-old also bowled the ball of the day to dismiss Kim Garth for a golden duck, jagging it back from outside off stump to take middle and leg.

And just as the Stars looked set to work their way into the game, Darlington had Maia Bouchier caught on the legside boundary for 23.

Having made her Australia debut at 19, Darlington is now pressing for her first national selection in two years after taking 13 wickets in her last four WBBL games.

Her work with the ball came after the Thunder looked down and out. Only Heather Knight's 45 helped the host's innings stay afloat, after they slumped from 30 for 0 to 39 for 3 early and were always rebuilding.

Teenager Rhys McKenna, in particular, bowled superbly for Stars, while Sutherland took 3 for 22.

Thunder's victory moves them back ahead of Adelaide Strikers in first place, with six wins from seven games, after collecting the wooden spoon last season.