Brisbane Heat 179 for 7 (Wyatt 52, L Harris 44, Smith 3-21) beat Hobart Hurricanes 135 for 8 (Lee 47, Villani 25, Jonassen 4-23) by 44 runs
In the Eliminator, a must-win match between the third and fourth ranked teams, Heat grabbed a stranglehold of the contest with a high-octane batting effort after being sent in at Adelaide's Karen Rolton Oval.
Wyatt dominated early before Harris took over to power Heat to a huge total that proved too much for Hurricanes, who were playing their first final since the WBBL's second edition in 2016-17.
Heat will play Adelaide Strikers in The Challenger at the same venue on Thursday for a spot in the final against Sydney Sixers.
Wyatt lays strong platform
The attention was on Georgia Redmayne, who returned for the Heat after missing the past four matches due to a hamstring injury. She had been the WBBL's leading run-scorer at the time, but was rusty early on a pitch offering some movement.
Fortunately, she was able to take her time with opening partner Wyatt in commanding form as Heat smashed their second best powerplay of the season with 33 runs.
Wyatt played bravely and monstered anything overpitched, helped by some inconsistent bowling from Heat, as she rattled spinner Molly Strano with her aggressive approach.
The loss of a scratchy Redmayne for 14 did little to halt Wyatt, who reached her second consecutive half-century with a gorgeous cover drive to the boundary.
But she fell shortly after to a superb wrong'un from Amy Smith's second delivery to spark a Heat collapse, where they lost 3 for 6 mid-innings.
Harris plunders Heat in near record
There was no consolidation from big-hitter Harris, who counterattacked with pure striking to turn the game in a 14-ball whirlwind
She wisely backed herself and took the power surge in the 14th over, where Harris took charge against seamer Hayley Jensen with three straight boundaries and a six to cap a 23-run over.
Harris continued her destruction in the power surge as quick Heather Graham could do little to stem the momentum.
Harris eyed Melbourne Stars teenager Tess Flintoff's 16-ball fastest-ever WBBL half-century, but that record bid was dashed when she was bowled by Nicola Carey in the 15th over.
Heat enjoyed a late flurry through Charli Knott and Nicola Hancock to lift them to a mammoth total.
Villani and Lee start confidently in the chase
To chase the formidable target, Hurricanes needed a strong platform and they did exactly that through Villani and Lee.
They pounced on ragged bowling from Heat who were unable to find their lengths. Villani and Lee capitalised under the lights to power Hurricanes to 37 runs in the opening four overs in their second best powerplay of the season.
Skipper Jess Jonassen tried to steady the ship and took matters in her own hands in the sixth over but her first delivery went to the boundary marked by a sloppy misfield, as Villani and Lee notched their half-century stand.
Hurricanes remained on course until Villani was run-out in the eighth over after superb fielding from Knott at point changed the course of the game.
Heat take care of business
Heat stymied Hurricanes after the wicket of Villani as the pressure rose on Lee, who struggled to recapture her earlier fluency. Hurricanes started to fall badly behind the required run and took the power surge in the 12th over in a bid to get back into the contest.
But seamer Courtney Grace Sippel bowled superbly to snare the big wicket of Lee in a clutch over costing just one run.
Hurricanes' chase fell apart from there as Jonassen finished superbly to level Strano as the WBBL's highest-ever wicket-taker. It was a statement win for Heat, who made amends after bowing out at the Eliminator last season.