Shaun Tait took a hat-trick as Nottinghamshire collapsed to lose by 47 runs to Essex in their Friends Life t20 quarter-final.
Ryan ten Doeschate hit 82 as Essex posted 187-6 off their 20 overs, with Ravi Bopara wading in with 38 and Ian Butler taking 3-23.
Skipper David Hussey top-scored for the Outlaws in reply, but his side lost their last six wickets for 13 runs in just 11 balls, with Tait taking a hat-trick, as they collapsed to 140 all out.
Essex's reward for winning is a draw against Northants at finals day at Edgbaston on August 17, while Hampshire will play Surrey.
Put in to bat, in front of a crowd of 12,106, the Eagles were floundering on 46-3 when Ten Doeschate arrived at the crease.
He had some good fortune early on, as a confident shout for lbw was turned down when he had made only six. Replays seemed to suggest that the bowler, Butler, was unfortunate, with the ball looking to be going on to clip the stumps.
Ten Doeschate went on to score his runs from just 44 deliveries, hitting five fours and five sixes, while Bopara made 38 from 25 balls, and shared in a stand of 72 with the Holland international to give the innings needed impetus.
Requiring more than nine an over, the home side began brightly, putting 42 runs on the board in 18 balls before being undone by David Masters (3-26).
The 35-year old accounted for Alex Hales, Michael Lumb and James Taylor within the space of eight deliveries.
Hussey and Riki Wessels, who made 22, added 63 in eight overs together, but the run rate spiralled out of control and Nottinghamshire's defeat was hastened by Tait, who ended with figures of 4-29 as the innings folded for just 140 in 17.2 overs.
For the third year in a row Nottinghamshire slumped to quarter-final defeat, while the Eagles, who finished third in the southern qualifying group, now advance to their fourth appearance at finals day and will take on Northamptonshire Steelbacks a week on Saturday.