Surrey 60 for 0 (Finch 44*) beat Glamorgan 183 for 8 (Lloyd 39, T Curran 3-30) by 24 runs (D/L method)
A sense of uncertainty hung in the Cardiff air. Glamorgan and Surrey's Blast campaigns had both been plagued by inconsistency, but tonight's game had all the makings of a thriller: two sides battling it out with the tantalising prospect of a potential quarter-final in the offing.
This was set to be either a winner-takes-all showdown or an effective dead rubber depending on how in-form Sussex fared against bottom club Middlesex, but there was no suggestion that this game would be a lowkey end-of-season affair.
And after Glamorgan posted a competitive 184 despite a post-powerplay lull, the stage was set for a humdinger. Instead, it turned into the dampest of squibs.
The run chase was delayed by half an hour due to rain, and after three dry overs - which Surrey smashed for 41 - the heavens opened again.
The umpires kept the players on in the hope of reaching the magic five-over mark, but the ball was like a bar of soap, and by the time Ingram bowled the final ball of that fifth over - which Aaron Finch swotted down the ground for six - the downpour was heavy, with Surrey were 24 ahead of the DLS par score.
The covers returned, and attentions turned to Hove, where Middlesex were well set in pursuit of 216; despite a terrible campaign with the bat, they had cut the required rate to 8.5.
Glamorgan were all but out as the rain continued to fall, and Surrey sat praying for a favour from their London neighbours. But it didn't come: Middlesex slipped from 158/3 to 184 all out, and Sussex's quarter-final place was confirmed.
Surrey's captain Jade Dernbach said: ""We always knew we had to get a win coming into this game with other results going our way but it was not to be. The phrase missed opportunities during our campaign comes to mind. We have to dust ourselves down quickly and know we have a huge six weeks ahead with the chance of winning the county championship."
It was a disappointing end to a game that had promised so much at the halfway stage. Glamorgan's 184 looked like a handy score albeit on a wicket that offered little for the bowlers, and with Surrey missing Jason Roy - missing due to a self-inflicted injury caused by throwing his bat in anger due to a duck on Wednesday only for it to bounce back into his face - the partisan home crowd had reason to hope for a tight game.
Glamorgan got off to a flying start thanks to their top three's pyrotechnics, as Colin Ingram, Craig Meschede, and Aneurin Donald all slammed early boundaries off the seamers. But all three fell before the end of a frenetic powerplay which brought 74 runs, and David Lloyd and Kiran Carlson decided to take stock.
Gareth Batty bowled impressively, going at under 6 runs an over, but Carlson, Lloyd, and Chris Cooke's cameos led the charge towards 200. Tom Curran impressed at the death - he took 2-10 in his final spell - to leave the game in the balance at the interval.
After a couple of early Surrey boundaries, the third over of the chase, bowled by Timm van der Gugten, proved decisive. Finch, whose record in this competition comes with parental advisory for explicit content, crunched his second ball for six down the ground, then three fours in succession, before slamming his final ball into the stands over cover. The over cost 24 runs, and took Surrey 20 ahead of DLS par.
Finch's 16-ball 44* took him to 589 runs for the tournament, with an average of 147.25 and a strike-rate of 182.
For Glamorgan, an early exit represents a disappointment after topping the South Group last season. Tonight summed their problems up well. While they got off to a flying start, their top six all reached 20 but failed to reach 40, and in admittedly tough bowling conditions, they had no real plan to contain Finch.
While they were hugely impressive in wins at the Oval and the Ageas Bowl, they struggled to find the consistency managed last season, and defeats in their final three games proved crucial.