Hampshire's reward for beating Nottinghamshire in the final NatWest t20 Blast quarter-final at Trent Bridge is a clash with Lancashire on Finals Day, while Surrey will face the Birmingham Bears at Edgbaston on August 23.
Captain James Vince led the way for Hampshire with an unbeaten 93 off 51 balls, with 11 fours and four sixes, to help his side to a five-wicket victory over the Outlaws, whose imposing total of 197 for two was overhauled with an over to spare.
It ensured Vince's team reached their fifth consecutive Finals Day and the 2010 and 2012 winners will come up against Lancashire, who sealed their place in the last four with a one-run victory over Glamorgan in a match that went to the wire at Emirates Old Trafford on Saturday.
In the other semi-final, the Birmingham Bears will be hoping to make home advantage count against last year's runners-up Surrey.
The Bears defeated Essex by 19 runs at Chelmsford on Saturday, while Surrey claimed a three-wicket victory over Worcestershire at the Kia Oval.
The order of the semi-finals has not yet been revealed, with the England and Wales Cricket Board to confirm at a later date.