New South Wales 7 for 259 (Warner 108, Bird 3-52) beat Tasmania 9 for 258 (Jewell 70, McDermott 68, Dwarshuis 4-50) by three wickets
David Warner's century helped New South Wales to victory over Tasmania in the top-of-the-table clash in Hobart putting them on track to play in next month's final.
The chase had a wobble late on as three wickets fell for six runs - Jackson Bird striking twice in an over including the scalp of Warner - but Sean Abbott and captain Pat Cummins took them to the brink.
Tasmania had made the early running with an opening stand of 138 in 19 overs between Caleb Jewell and Ben McDermott, but their innings faltered badly losing 6 for 40, and they needed lower-order contributions from Bird and Nathan Ellis to make their way beyond 250.
Warner and Moises Henriques formed the backbone of the chase with a stand of 96 in 16 overs, which put New South Wales well ahead of the required rate, although Tasmania were poor in the field with Warner dropped twice and their problems were compounded with Ellis only able to bowl three overs.
However, Warner also had a significant stroke of fortune on 66 when he was given not out caught down the leg side against Peter Siddle off what appeared a glove. In the next over he then crunched a drive just over the fingertips of Bird at mid-off.
His century arrived from 104 balls and followed the 87 he made in the previous one-day match against South Australia.
After Kurtis Patterson was lbw missing a reverse sweep off Beau Webster, Ollie Davies contributed a flamboyant 28 as he outscored Warner in their partnership, before poor shot selection had him fending a short ball from Riley Meredith in his final over. That opened the door for Tasmania with Nick Larkin and Warner both edging to Tim Paine (who took five catches in the innings) but the visitors held firm.
New South Wales, under the captaincy of Cummins for potentially the final time this season depending on when he leaves for the IPL, were given the runaround early as Jewell and McDermott flayed the bowling although Cummins was a notable exception as he sent down two maidens in his first four-over spell.
Jewell was the more aggressive but McDermott, who had recovered from a hamstring injury suffered in New Zealand and then didn't take the field during New South Wales' innings, wasn't far behind. Left-armer Ben Dwarshuis removed them in consecutive overs as the wheel turned with Abbott then taking a sharp return catch to claim Paine.
Matthew Wade was lbw to Liam Hatcher and Nathan Lyon, who had figures of 6-0-39-0 at one stage, claimed 2 for 5 in his last four overs. It looked like Tasmania would get bowled out but Webster, Ellis and Bird prevented that and if they had fielded better the result could have been different.