Surrey secured a home semi-final in the Natwest T20 Blast despite suffering a defeat to Kent in their final group game.
Chasing 176 to win at Canterbury, they eventually came up 21 runs short, but scored enough runs to ensure they finished second ahead of Hampshire on run rate.
That means they will host Worcestershire in the last eight at the Oval on Saturday, with a 2.30pm start.
It was a disappointing finale for Surrey, who looked well in command of their run chase at Canterbury until a brilliant over from Mitch Claydon turned the game around.
The visitors had just lost Kevin Pietersen for 32 when Claydon came back into the attack with the score at 125-3, 51 required from four overs.
His first ball was a beauty of a yorker which cleaned up Azhar Mahmood, and his second was well caught by Fabian Cowdrey to send Rory Burns back first ball.
Ben Harmison dropped a catch two balls later, but Robin Peterson was run out when he and Gary Wilson were on completely different wavelengths as the South African chased a leg bye.
Wilson made 31 but perished in the next over, and the asking rate just got on top of Surrey.
Earlier, Darren Stevens (67) and Alex Blake (45) had led the way as Kent posted 175-7 in their 20 overs.
They had been three down inside the powerplay, but Stevens and Blake eventually put on 90 in eight overs for the fifth wicket to propel the Spitfires to a big total.
Surrey's reply got off to a blistering start thanks to Steven Davies - who was a late replacement after Jason Roy suffered a minor injury in the warm-up - and Tillakaratne Dilshan, and Pietersen and Wilson looked to have them well on course, until their late implosion saw them beaten by Kent for the second time in a week.
