Yorkshire 161 for 9 (Lyth 64, Ball 3-30) beat Somerset 162 for 8 (Overton 79*, Hill 2-12) by 2 wickets

Defending champions Somerset are through to their sixth successive Vitality Blast Finals Day after Craig Overton played one of the all-time great innings - 79 not out off 30 balls - to grab a two-wicket victory from the jaws of defeat chasing 162 against Yorkshire at Headingley.

A career-best innings, including eight fours and five sixes, recovered Somerset from 82 for 8 in the 15th over and achieved 22 off the last over from Matthew Revis, winning with a ball to spare.

Overton added to his earlier two wickets to ensure Lewis Gregory's side will target a third title in four years at Edgbaston on Saturday after restricting Yorkshire to 161 for 9. Fellow seamer Jake Ball claimed 3 for 30.

Opener Adam Lyth top-scored with 64 for Yorkshire, but the hosts felt short as they missed out on the chance to win a maiden Blast title when looking nailed on to win.

While Yorkshire were not short on early boundaries having elected to bat, they ended the powerplay in trouble at 45 for 3. Moeen Ali, promoted to open, edged behind against Overton for a golden duck, Ball got Will Luxton caught behind down leg and Jonny Bairstow was bowled by Australian Riley Meredith.

Yorkshire's all guns blazing approach on flat Headingley pitches has served them so well during the group stages but had to be reined in. Lyth still hit sixes over long-off and long-on and reached his fifty off 31 balls as Yorkshire moved to 82 for 3 after 10 overs.

He shared 58 with fourth-wicket partner George Hill, who contributed 19 before both fell in successive overs - 103 for five in the 14th. Lyth was caught at short third off a top-edged pull at Overton.

Their departures were key just as the bulk of the rebuilding had been done. And, from there, a brilliant and disciplined Somerset effort - they only conceded four extras - squeezed the life out of the innings.

Australian Daniel Sams, who had earlier removed Hill, struck again, so too Ball twice and Meredith twice. Ball got Dom Bess and AJ Tye caught in the deep and behind. Yorkshire felt a long way short with their total.

There, however, renewed hope when Hill's seam forced a miscue from Thomas Rew to mid-off before Tom Banton, released from England's ODI squad to play, edged Tye to slip to make it 18 for 2 in the third over.

Hassan had James Rew brilliantly caught one-handed running around from midwicket by Bess before superb Hill (two for 12) removed Will Smeed. Somerset were four down in the sixth over.

Former Yorkshire batter Tom Kohler-Cadmore was bowled by Dutch quick Logan van Beek to leave Somerset 38 for 5 in the ninth. They needed 113 from the last 10 overs but lost Lewis Goldsworthy to Revis.

Further wickets made the chase look forlorn before Overton - he reached 50 in 22 balls - attacked with freedom, hitting three leg-side sixes in the last over and set up a morning semi-final meeting with Northamptonshire. A single through cover won it.