Jonny Bairstow was Yorkshire's star as they booked a place in the Friends Life t20 showpiece with a 36-run win over semi-final opponents Sussex in Cardiff.
The Tykes, in their first finals day appearance, put on a formidable 172 for six as England's Bairstow (68 not out) and South African David Miller (47) shared a key fourth-wicket stand of 82.
Sussex danger men Luke Wright and Matt Prior both failed, but Chris Nash made a superb 80no from 58 balls in a losing cause.
Sussex had started the day well, with Scott Styris producing a superb spell of three for 22 with the new ball.
Yorkshire skipper Andrew Gale was first to go, deceived by a slower ball, and was soon joined by Phil Jaques and a skittish Joe Root as Styris maintained a testing line.
Only Bairstow bested the New Zealander, clubbing him for six from his fifth delivery before he joined Miller for a busy but responsible stand that passed 50 in 44 deliveries.
Miller was the chief aggressor, attacking Chris Liddle and lifting him into the River Taff in the 11th over.
He had four fours and two maximums when he was caught at long-on, by which time Bairstow had comfortably found his range.
His half-century came with a sweetly-timed six off Nash and he cleared the ropes for a third time when lifting Amjad Khan over fine-leg.
Gary Balance (seven) and Bresnan (six) came and went but Bairstow kept things going to finish with 68 not out from 45 balls.
Nash got Sussex's chase under way with a remarkable paddle-sweep for six but Yorkshire quickly made their mark removing two star men in the space of five balls.
Wright was first to go, bowled for three off the inside edge by Ryan Sidebottom and he was followed moments later by in-form England wicketkeeper Prior.
Prior's Test team-mate Tim Bresnan was the bowler, cramping him for room and drawing an awkward shot to have him caught at mid-on for only two.
Nash was doing the bulk of his side's scoring, with 34 of the first 50 runs, but he lacked support - Murray Goodwin the next to go for 15 as he chipped Richard Pyrah down the ground.
At the halfway mark Sussex were well short on 60 for three and things did not improve from there.
Nash continued to impress whenever he took strike, scoring boundaries at will, but none of his next six partners reached double figures.