Gardner's Giants hold nerve in WPL thriller

That included taking 20 off the penultimate over bowled by Gardner. 

The first ball of that over had gone through the hands of a leaping Georgia Wareham for six and both Aussies must have feared the worst when it ended with nine needed off the final over.

Sophie Devine's last over had gone for 23. But Gardner backed her Kiwi allrounder to repeat the heroics of this pair's previous meeting this season when Devine defended seven in the final over after a similar late Delhi rally.

The skipper's faith was justified as Devine conceded five runs, taking two wickets -  one caught by Wareham on the boundary, the other by Gardner, to win the game by three runs. 

The win means Giants will make the play-offs if they beat Mumbai Indians on Friday (Saturday 0100 AEST) while Capitals must beat Meg Lanning's Warriorz on Sunday (Monday 0100 AEST) to do so.

"I felt I owed it to Ash," said Devine. "I got pumped in one of those overs and brought them back in. I tried to stay calm and keep it as simple as possible."

Earlier Beth Mooney's 46-ball 58, her first half-century of this year's tournament, had provided the framework for Giants to make 9-174.  

"I've been hitting the ball well, it just hasn't happened for me in this tournament so far," said Mooney. "Thankfully I'm in a team of matchwinners."

With Anuska Sharma (39 off 25) and Tanuja Kanwar (21 off 11) injecting some pace Giants' total looked likely to be enough.

That seemed even more so when Delhi slumped to 6-100 with 33 balls left and the star South African trio Lizelle Lee, Laura Wolvaardt and Marizanne Kapp all out.

But Indian youngster Niki Prasad (47 off 24) and experienced Sneh Rana (29 off 15) almost engineered an unlikely Capitals win.

"We are in the entertainment industry at the end of the day and we entertained," said a relieved Gardner. 

"We did our job with that - but my heart rate was going through the roof in that last over."