Brisbane Heat 172 (McSweeney 73, Sams 5-30) beat Sydney Thunder 157 for 9 (Bancroft 46, Bartlett 3-29) by 15 runs

Brisbane Heat defied a horror collapse and a historic Daniel Sams spell to beat the Sydney Thunder by 15 runs and stay unbeaten in the Big Bash League.

The hosts were flying on Wednesday at the Gabba on the back of Nathan McSweeney's (73 off 52) delightful innings, before they lost 7 for 16 to be all out for 172. Sams took four wickets in his final over and finished with a career-best 5 for 30 to claim Thunder's first five-wicket haul.

Cameron Bancroft (46 off 39) was engineering the Thunder's chase nicely but came undone in a decisive 14th over.

Calling for the power surge at 97 for 2, the opener was immediately dismissed as Xavier Bartlett (3-29) went for just three runs off the bat and a leg bye.

Ollie Davies, who would have been out second ball if Mitchell Swepson had reviewed an lbw shout, then threatened to play the decisive hand.

But Matthew Kuhnemann (2 for 25) outfoxed his man, sprinting for a sharp caught-and-bowled, and Sams was out in the next over. A direct hit from Michael Neser then caught Nathan McAndrew just short to kill off any hope of a successful chase, the Thunder finishing the innings on 157 for 9.

Victory put the Heat clear on top of the ladder with four wins and a washed-out no result ahead of Perth, while the Thunder slipped to 1-3. Earlier the Heat were on track for an imposing total, McSweeney and Josh Brown (39 off 29) putting on 106 after Colin Munro was caught at deep square leg for a golden duck.

Big-hitter Brown unusually took the back seat as McSweeney powered the innings with pure stroke-making and clever placement. Cameos from Matt Renshaw and Sam Billings moved them to 156 for 3 before the rot set in, Sams' changes of pace making the Heat's lower order look foolish.

He had McSweeney caught at cover before Bartlett, Spencer Johnson and Mitchell Swepson were undone by slower balls. The allrounder was unlucky not to jag a hat-trick with Swepson's mistimed slog falling just short of the bowler's feet.

Thunder fell into the same trap though, Brisbane's spinners triggering a 29-ball period without a boundary before the wickets tumbled.