WBBL Final: Thunder wins in thrilling showdown with Sixers | Photos

Sydney Thunder captain Alex Blackwell revealed she almost "fainted" from screaming too hard after her team defeated cross-city rivals the Sydney Sixers for the inaugural Women's Big Bash League title at the MCG.

The Thunder was set what appeared a comfortable 116 for victory after an outstanding performance by Blackwell's bowling attack, spearheaded by spinner Erin Osborne, who snared 3-21.

However, the Thunder seemed to be on the ropes after going into the last over having lost their previous five wickets for 13 runs. 

In the 18th over, Sixers skipper Ellyse Perry dropped a catch, but rather than drop her head she threw the ball to her 'keeper Alyssa Healy to run out opener Rachael Haynes for 37.

With nine runs required from 12 balls Nicole Carey was run out, setting the stage for South African fast bowler Marizanne Kapp to do something special, and she did not disappoint - dismissing Blackwell for 30. 

Then, with seven runs runs needed rom eight balls, Osborne was run out going for a second run.

Rene Farrell and Claire Koski needed four to win from the final over - and many of the 5000-strong crowd were biting their nails as Perry charged in and removed Farrell with the second ball. 

The pressure was incredible as seventeen-year-old Lauren Cheatle took strike with two runs needed from three balls. She seemed to be in trouble when she ran a bye and Perry ended up with the ball.

In the final twist of a match that had everything Perry's attempt for a  run out missed and the subsequent overthrows was the signal for the Thunder's squad to charge onto the field in triumph.

"I think I nearly fainted," Blackwell laughed.

"We were screaming our heads off when we realised we'd actually won, it was a little bit confusing on that last ball.

"I had everyone around me  ... they were propping me up ... I had got a little bit light headed from screaming which is a nice feeling. It's better than [holding her head] and saying 'no!'"

"It's a great feeling and until it's actually done you don't want to jump the gun because anything can happen in cricket."

Perry won the toss and elected to bat, saying she wanted runs on the board. But  the 116 the Thunder were set never seemed enough.

Despite some missed chances, Erin Osborne tormented the Sixers' batters to take three wickets; teenager Maisy Gibson snared 2-21 and Rene Farrell finished with 2-22.

A disappointed Perry conceded her team finished 20 runs too short but she took heart in her team's refusal to give in.

"Everyone was up for the challenge and the contest out there and it was really nice to do that as a unit in the field and I think our bowlers were spectacular," she said.

"Staying in there like that and making it go down to the last over was really great and quite defining, I think, of our team this season."

Many of the Sixers batters made starts, opener Alyssa Healy scored 19, Ashleigh Gardner scored a rapid-fire 20, Sara McGlashan scored 20 while Angela Reakes  hammered  23.

While it took the Thunder a pain-staking nine balls to score their first run, their openers Stafanie Taylor and Rachael Haynes managed something their arch rivals couldn't - a solid partnership. 

When Taylor was caught by Ashleigh Gardner for 27, she and Haynes had compiled 56. When Naomi Stalenberg was dismissed in the same over it brought Blackwell to the crease and she brought a sense of purpose before falling for 30.