Hampshire captain James Vince scored an unbeaten 93 as the Hawks overhauled Nottinghamshire's 197-2 to reach the NatWest Blast T20 Finals Day.
It will be Hampshire's fifth successive trip to the domestic game's showpiece occasion but they looked almost down and out after Riki Wessels' 62 not out in 41 balls helped Notts to a huge total at Trent Bridge.
But Vince blasted four sixes and 11 fours in his 51-ball knock and with Michael Carberry chipping in with 31 and Sean Ervine making 39, Hampshire got home with a full over to spare.
Hampshire's reward is a semi-final clash with Lancashire on Finals Day, while Surrey will face the Birmingham Bears at Edgbaston on August 23.
Wessels top-scored with 62 not out for Notts, Samit Patel finished unbeaten on 53 and Alex Hales blasted 51 at the top of the order.
In pursuit of 198, Hampshire got off to a flying start, with Vince taking four boundaries from the second over, bowled by Harry Gurney.
On 20 he was reprieved, though, as Hales spilled a fierce drive at cover off Ajmal Shahzad's bowling.
Michael Carberry was stumped for 31 at the start of the eighth over as the bowler, Patel, became the first Notts player to take 100 wickets in the domestic T20 competition.
Vince reached his 50 with a six off Patel, it coming in 31 deliveries with eight fours also, but he then lost Glenn Maxwell and Jimmy Adams to consecutive deliveries from Shahzad.
Notts missed out on a further scalp as Patel badly misjudged a catch in the deep, deliberately grounding the ball, fearing he was going to topple over the ropes when he was in fact some way from the boundary.
The batsman, Sean Ervine, was on 11 at the time and provided the necessary support to Vince, although both he and Will Smith both perished to Luke Fletcher with the finishing line in sight.
Fletcher closed with figures of 2-26 but conceded the winning single to Coles.
Michael Lumb made 22 from 11 deliveries at the start of the Notts' innings before muscling Matt Coles out to deep midwicket.
A streaky inside-edge got Wessels' innings under way but the then levered Kyle Abbott high over the leg side for his first maximum.
Hales twice put Danny Briggs over the ropes to reach his 50 from 39 balls, with four fours and two sixes, but then also fell to a catch in the deep.
Wessels and Patel kept up the momentum, going on to add 79 in just seven overs together.
Although both passed 50, the total only looked around par on a good surface and was eventually chased down in 19 overs by the visitors.
It was the fourth quarter final in a row that Notts had lost at home but Hampshire go through to Finals Day, where they will face Lancashire.