Gloucestershire 138 (Bancroft 43, Foulkes 3-22) beat Birmingham Bears 124 for 9 (Payne 4-23, O Price 3-32) by 14 runs
Birmingham Bears suffered a fourth consecutive quarter-final exit as Gloucestershire stunned the North Group winners with a 14-run victory in a tense, low-scoring contest at Edgbaston.
The west country side scraped into the last eight only on net run rate, finishing fourth in the South Group, but will now face Sussex in the semi-final back on this ground on Saturday week.
Gloucestershire had looked well under par, racing to 51 without loss from five overs after being put in only to be bowled out for just 138.
But as left-arm quick David Payne took 4 for 23, including two as he defended 18 but conceded just three in the final over, and spinner Ollie Price 3 for 32, the Bears could muster only 124 for 9 in reply, Chris Benjamin's 33 a paltry top score.
Cameron Bancroft had top-scored for Gloucestershire with 43 in 35 balls and opening partner Miles Hammond 30 from 24 but no one else bettered Jack Taylor's 19.
Bears' New Zealand seamer Zak Foulkes took 3 for 22, spinners Danny Briggs and Dan Mousley picking up two wickets each and George Garton executing two magnificent run-outs with direct hits.
Needing to score at just under seven-an-over, Bears were 37 for 2 in the powerplay, 17 behind their opponents at the corresponding point and with one fewer wicket in hand.
Payne, who opened with a maiden, had Alex Davies caught on the square leg boundary and struck a major blow to the home side when Moeen Ali was out for 27. Payne had conceded 16 of those himself as the England man hit him for six, four and six but the next ball found the outside edge and James Bracey took the catch.
Like their counterparts in the first innings, Bears struggled to regain their momentum, losing Mousley leg before in an attempted pull and Jacob Bethell caught at extra cover, both wickets falling to Ollie Price, leaving them 59 for 4 in the ninth. That became 74 for 5 in the 13th as Price's offspin claimed its third victim, Sam Hain unleashing a towering hit on the leg side but failing to clear Hammond on the midwicket boundary.
Benjamin hammered six off Tom Smith and Garton took two fours off Price to ease the pressure but then Josh Shaw ramped it up again with two wickets in two balls as Garton holed out to long-off and Foulkes perished leg before.
It all came down to 18 required off the last six balls, with Gloucestershire pace man and leading wicket-taker Payne coming out on top, conceding just three and adding the wickets of Benjamin and Jake Lintott for good measure as Price and Bancroft held catches in the deep.
Gloucestershire fans must have been anticipating a big score when Hammond and Bancroft helped them put 54 on the board from six.
Bancroft's scoop brought him two of three fours in Foulkes's opening over and Hammond pulled Mousley for six but the offspinner had revenge when Hammond was caught by a tumbling Lintott at mid-off.
The Bears spinners then wrestled back control, Briggs beating Bracey's swing across the line for a leg before, Ollie Price top-edging the same bowler to short fine leg. A chance was missed when Bancroft was dropped on 30, but the return of pace saw Jack Taylor's attempted pull go vertical, dropping into the gloves of keeper Davies.
Ben Charlesworth clobbered Moeen over the midwicket boundary but perished looking for a repeat next ball and then Bancroft, for whom something substantial now looked vital, was brilliantly run out by Garton's direct hit from long-on.
Panic now set in. Matt Taylor and Shaw were caught off consecutive balls from Foulkes, another precision throw by Garton ran out Matt Taylor from mid-on and Payne sliced Mousley in the air to backward point, leaving Gloucestershire all out for what looked like a seriously under-par 138, but turned out to be enough.
