Having won the toss and electing to bowl, the Thunder got off to a good start having the Stars at 3-55.
Pete Handscomb and Seb Gotch (31) managed to combine for a 49-run partnership with Handscomb scoring a half-century.
John Hastings and Evan Gulbis then took the Stars to 6-147 after 20 overs.
In reply, the Thunder started very well with an opening stand of 85 from Usman Khawaja (44) and James Vince (40).
Liam Bowe was the pick of the bowlers with 2-30 from his four overs.
The Stars will next face the Sydney Sixers at the SCG on Tuesday night.