During opening weekend of WBBL|05, the Heat prevailed by 92 runs.
Despite an impressive 2-19 from four overs by South African leg-spinner Dane van Niekerk, the Heat won with 19 balls to spare finishing 3/127 in reply to 7/123.
Heat openers Beth Mooney (25) and New Zealand International Maddy Green (25) reached 44 without loss in the powerplay before losing their first wicket on 46 in the seventh over.
Van Niekerk then dismissed the dangerous Mooney, with a sharp caught and bowled, and the Sixers were in the game at 2-69 in the 11th.
However, Jess Jonassen (33 from 28) and Grace Harris (26 not out from 18) steered the visitors home.
Earlier, Sixers captain Ellyse Perry won the bat flip and elected to bat first, but it was the Heat who enjoyed the perfect start, with both the skipper and Alyssa Healy unable to reproduce their unbeaten 199-run partnership against the Stars last match.
Both were dismissed for single figures and the Heat did a good job therein to restrict the run rate.
Four batters passed 20, including van Niekerk who made 28 from 32 balls, with Australian spinner Jess Jonassen (2-20) and Delissa Kimmince (2-26) multiple wicket takers for the visitors.