Hampshire 186 for 5 (Wheater 78) beat Surrey 157 for 9 by 29 runs
Teenage leg-spinner Mason Crane took 2 for 35 on his full debut to help Hampshire to a seventh straight home victory against Surrey.
Crane, who was plucked from taking a five-wicket haul for the second team yesterday to replace the injured Chris Wood in the side, claimed the legendary Kumar Sangakkara as his first professional wicket.
Adam Wheater had early struck his highest T20 score of 78, beating his previous best of 36, as Hampshire won by 29 to rekindle their quarter-final hopes.
After being put in by Gareth Batty, James Vince brought up the first boundary of the night in the second over by dancing down the wicket and slashing through point, before he followed it up with another four through the same region next ball.
Michael Carberry took a liking to James Burke's short and wayward bowling, dispatching him for four boundaries in a row, before he sliced to Jason Roy at backward point.
Vince, with Wheater, thwacked a stand of 50 for the second wicket off 23 balls before the skipper edged to Tom Curran at short third man off Zafar Ansari for 31.
Wheater kept the score ticking along with his textbook reverse sweeps and straight drives, and he reached a deserved half-century from 29 balls - as he and Owais Shah added 84 for the third wicket.
Wicketkeeper Wheater continued his assault of the Surrey bowling and just managed to clear the man on the boundary to hit his only six, but departed soon after for a sweet 78 off 49 balls.
Veteran Azhar Mahmood returned the pick of the bowling figures - 2 for 19 - including two in two deliveries in the penultimate over, Shah picking out Roy for 37 before Will Smith came and went.
Hampshire ended on 186 for six, and Surrey's reply started in stuttering style as Jason Roy collected a boundary with typical oomph, but opening partner Curran chipped nervously to Vince at extra cover.
Jackson Bird made it two wickets in three Hampshire deliveries to comprehensively bowl England one-day smasher Roy for a subdued nine.
Sangakkara and Vikram Solanki, who have a combined age of 76, got the visitors back on track to end the powerplay on 50 for two.
Spin sensation Crane excelled in his opening over in first-team cricket with four dots and a tough caught and bowled chance. And the 18-year-old had the moment of his life in his second over when Sri Lankan Test star Sangakkara hit a full toss to a sprawling Joe Gatting.
Smith trapped Rory Burns in front in the next over as spin turned the game in Hampshire's favour. Crane picked up an important second wicket with a guileful leg break which beat the outside of Solanki's bat before Wheater simply stumped him for 34.
Zafar Ansari came and went - smartly snatched behind - as Smith ended with impressive figures of two for 17 - before Danny Briggs got in on the act to see off Ben Foakes.
The late wickets of Burke and Mahmood completed the Surrey collapse as Hampshire got their T20 Blast campaign back on track in front of a highest Ageas Bowl crowd for two years.