Dwarshuis (4-13, 3.5 overs) narrowly missed out on becoming the first Sixers men's player to claim a hat-trick, but was a strong contributor at the MCG on Thursday night.
The left-arm seamer was part of a bowling unit that strangled the Stars, knocking them over for 128 in 19.5 overs, before Lachlan Shaw (24no off 14) and Jordan Silk (18no off 20) steered the visitors home.
They reached 4-129 with 17 balls to spare.
It was the Sixers' (4-3) third straight win, setting up a possible title charge with Test stars Mitchell Starc and Steve Smith, plus off-spinner Todd Murphy, set to feature in the back-end of the competition.
The Stars (4-3), meanwhile, have nosedived with three straight losses after their hot start to the campaign.
The Sixers didn't require anything special and always looked in control during their run chase, with Josh Philippe (35 off 25) top-scoring.
Stars captain Marcus Stoinis (2-21, four overs) fought hard in an attempt to drag his side back into the contest.
Earlier, left-arm spinner Joel Davies (2-15, four overs) put the clamps on the Stars, who were sent in to bat and only briefly lifted their run rate above eight an over.
Stoinis (33 off 35) and Blake Macdonald (33 off 22) top-scored for the home side, but both fell victim to Dwarshuis.
Dwarshuis bowled a double-wicket maiden in the 18th over, dismissing Stoinis and Haris Rauf in consecutive balls.
But he missed out on what would have been a historic hat-trick when Stars tailender Liam Hatcher played and missed a length ball outside off stump.
Jack Edwards (3-27) helped restrict the Stars to 2-17 in the power surge and removed key man Glenn Maxwell (one off four), who continued his lean season with the bat when he skied a catch.
Ben Manenti (1-15, three overs) was also important for the Sixers.
The Stars are back in action against cross-town rivals the Renegades on Saturday, while the Sixers host Hobart the following day.
