Jade Dernbach took 4-33 and Jason Roy hit 76 to script a four-wicket win for Surrey over Hampshire at the Rose Bowl.
Having chosen to bat first, Hampshire were skittled for 141 in 30 overs with seamers Dernbach, Yasir Arafat (2-39) and Tim Linley (2-21) all impressing.
Liam Dawson's 34 was the top score of a miserable effort from the home side, who nevertheless were in with a good chance after reducing Surrey to 45-5 in the 13th over of their reply.
Paceman Simon Jones (2-22) and spinner Danny Briggs (2-37) each struck twice but a 95-run, sixth-wicket stand between Jason Roy and Matthew Spriegel (29no) turned the game back Surrey's way.
Roy became a second victim for seamer Chris Wood with just two required, Chris Schofield (2no) duly finishing the job from Wood's next delivery.