Birmingham 189 for 5 (Evans 50, Woakes 48*) beat Essex 165 for 6 by 24 runs

Essex's target of 190 was a mammoth task. No team had ever chased so many in a Twenty20 tie at Edgbaston and predictably they fell well short. It was Birmingham Bears, the defending champions, who reached Finals Day with a 24-run win, their characteristic efficiency contrasting with the inconsistency of an Essex side that has once again failed to translate success in the group stages into a trophy.

It was a mucky night in Birmingham, a dodgy forecast enough to trim the crowd to 7,000. Here was one occasion, quarter-final or not, when the NatWest Blast's soaring attendances were not immediately apparent, but Birmingham will be back in front of a capacity crowd on August 29, their victory prepared by a half-century by Laurie Evans and an unbeaten 48 from 23 balls by the England allrounder Chris Woakes, back in action after a knee injury.

Essex lost two home quarter-finals against Birmingham last season, over both 20 and 50 overs. Such memories creep to the surface on nights like this. They were just about in the contest at 114 for 3, 76 required from the last six overs, but Jeetan Patel bowled Ravi Bopara with the final ball of his spell, as good as yorked by a quicker one.

"Our bowlers have been fantastic all tournament," said Varun Chopra, Birmingham's captain. They are quick to adapt and they executed brilliantly." Selection is tough-minded, too, legspinner Josh Poysden and seamer Ricardo Gordon missing out largely because it was a new surface. Woakes picked up the man-of-the-match award. "It's been a tough summer, picking up an injury after the World Cup, but it's great to be back out there," he said.

Jessie Ryder, spliced by Boyd Rankin and caught at mid off (so justifying Rankin's selection in a moment); Tom Westley, holing out at long-on; and Bopara all failed to press ahead for Essex after good starts, but that is often the outcome when the target, logically, is well beyond par. They got 165, which with a better display in the field might have been enough.

Only Hampshire have won more combined List A and Twenty20 matches than Essex since Paul Grayson became coach seven years ago. In one-day cricket, he has supervised consistently good results on a comparatively meagre budget, but on the big occasion, too often Essex have bombed.

With promotion in the Championship also now beyond them, the cricket chairman, Ronnie Irani, has given Grayson equivocal support at best - hardly the thing you need not long before the biggest night of the season.

Suggestions that Essex should have won trophies in that time might be persuasive, but they tend to emphasise the quality of their batting rather than the vulnerability of their bowling. Even their Australian overseas pace bowler, Shaun Tait, the second leading wicket-taker in the competition, is cricket's wild abstract artist, who daubs it on thick and occasionally comes up with a masterpiece.

The Edgbaston canvas did not suit Tait, as three overs for 37 told. Warwickshire were efficient with the bat, Essex were a mess with the ball. Two seasoned bowlers, Graham Napier and David Masters, broke down in the field - Essex could be grateful that Masters, at least, had finished his spell, their ground fielding was slovenly and they dropped catches too.

Things began reasonably well. The match was well balanced when Rikki Clarke was out at 88 for 4 in the 12th over, ten Doeschate forcing a leading edge to cover. But Evans and Woakes spurred Warwickshire on, sharing a fifth-wicket stand of 69 in 38 balls to take the total into unchartered territory.

Evans, though, was also fuelled by Essex errors. James Foster, at his peak, might have intercepted a tough chance high to his right, drawn by a Tait bouncer, before Evans had scored. Evans also survived on 14, slashing to backward point, but Tait had overstepped. On 46, ten Doeschate erred at mid off when Reece Topley should have got lucky with a full toss. When he finally fell for 50 from 31 balls, swatting Topley to midwicket, Birmingham piled on 32 from the last two overs with Woakes to the fore.

Less damaging, but most galling, was Foster's drop of a skier from Chopra, who got in a tangle against Shaun Tait's bouncer. Napier's claiming of the catch at mid off was an unwelcome intrusion, but Foster still had ample time to remedy matters only to overrun the ball and fumble the chance to the floor. He has seen off a lot of budding keepers in his time, and been a good Essex servant, but he had an off night at the worst time and at 35 his chances of a one-day trophy might be running out.

For Woakes, though, the feeling was one of contentment. His three Championship matches since his return from foot and knee injuries have brought 11 wickets at under 20 and now he has taken Birmingham a step closer to retaining their title.