Anika Learoyd carved out a career-best innings as Sydney Thunder started their WBBL campaign with a convincing six-wicket win over Melbourne Renegades in the season opener.

Learoyd made 48 from 37 balls after Georgia Voll did most damage with with her offspin in the first match of a double-header at Junction Oval on Thursday.

In at first drop, after Voll made 25 off 18, including Thunder's only six of the match, Learoyd hit nine boundaries and put on 62 with Heather Knight in a match-winning third-wicket partnership. The pair took 28 runs from the power surge to put Thunder within sight of victory.

Knight and Nadine de Klerk finished the job, guiding their team home with 18 balls to spare.

Learoyd admitted feeling "really nervous" batting near the top of the order, but will take confidence from starting the season with a strong performance.

"Probably a little bit of belief, I think," Learoyd told Fox Cricket. "It's not always something I'm great at, so it's really nice to feel like I can put the scores on the board and hopefully that will help me believe I'm good enough to do it."

Earlier, Voll's four wickets and hand in a run-out were crucial in restricting Renegades to 138 for 9 from their 20 overs.

"She was great, wasn't she? The true allrounder," Learoyd said. "She's been someone who I think is a really good contributor to our group with both bat and ball, and in the field as well. It was really nice to see her kick off a really good campaign."

Renegades opener Hayley Matthews gave her side a strong start with the bat, blasting 45 from 30 balls before holing out in the deep.

Matthews put on 56 for the first wicket with Courtney Webb, and Georgia Wareham made a handy 23 from 19, but a late-innings collapse cruelled their chances. Renegades lost 5 for 2 in the space of seven balls through the 17th and 18th overs as Voll wreaked havoc.